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THE INTERNATIONAL SCIENTIFIC SERIES. 
VOLUME XXXIII. 






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X 



V 



THE 

INTERNATIONAL SCIENTIFIC SERIES. 



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THE INTERNATIONAL SCIENTIFIC SERIES. 

— (To o^jz 

JON SO 1888 J 

ILLUSIONS 



A PSYCHOLOGICAL STUDY. 



BY 



JAMES SULLY, 

AUTHOR OF " SENSATION AND INTUITION," "PESSIMISM," ETC. 



NEW YORK: 
D. APPLETON AND COMPANY, 

1, 3, and 5 BOND STREET. 

1888. 



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4^ 



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vcA 



PREFACE. 



The present volume takes a wide survey of the field 
of error, embracing in its view not only the illusions 
of sense dealt with in treatises on physiological optics, 
etc., but also other errors familiarly known as illusions, 
and resembling the former in their structure and mode 
of origin. I have throughout endeavoured to keep 
to a strictly scientific treatment, that is to say, the 
description and classification of acknowledged errors, 
and the explanation of these by a reference to their 
psychical and physical conditions. At the same time, 
I was not able, at the close of my exposition, to avoid 
pointing out how the psychology leads on to the 
philosophy of the subject. Some of the chapters 
were first roughly sketched out in articles published 
in magazines and reviews ; but these have been not 
only greatly enlarged, but, to a considerable extent, 
rewritten. 

JL S. 

Hampskad, April, 1881. 



CONTENTS. 



CHAPTEE I. 

THE STUDY OF ILLUSION 

Vulgar idea of Illusion, 1, 2 ; Psychological treatment of subject, 3, 4 ; 
definition of Illusion, 4-7; Philosophic extension of idea, 7, 8. 

CHAPTEE II. 

THE CLASSIFICATION OF ILLUSIONS. 

Popular and Scientific conceptions of Minrl, 9, 10 ; Illusion and Halluci- 
nation, 11-13 ; varieties of Immediate Knowledge, 13-16 j fourfold 
division of Illusions, 16-18. 

CHAPTEE III. 

ILLUSIONS OF PERCEPTION : GENERAL. 

Psychology of Perception : — The Psychological analysis of Perception, 19, 
20 ; Sensation and its discrimination, etc., 20, 21 ; interpretation of 
Sensation, 22, 23 ; construction of material object, 23, 24; recogni- 
tion of object, specific and individual, 24-27 ; Preperception and 
Perception, 27-31 ; Physiological conditions of Perception, 31-33 ; 
Visual and other Sense-perception, 33, 34. 

Illusions of Perception : — Illusion of Perception denned, 35-38; sources 
of .Sense-illusion, 38-40 : (a) confusion of Sense-impression, 40- 44 ; 
(6) misinterpretation of Sense-impression, 44; Passive and Active 
misinterpretation, 44-46 ; Passive Illusions as organically and extra- 
organically conditioned, 46-49. 



Vlll CONTENTS. 

CHAPTEE IV. 
ILLUSIONS of perception — continued. 

A. Passive Illusions (a) as determined by the Organism. 

Results of Limits of Sensibility : — Relation of quantity of Sensation to 
that of Stimulus, 50-52 ; coalescence of simultaneous Sensations, 
52-55 ; after-effect of Stimulation, 55, 56 ; effects of prolonged 
Stimulation, 56-58 ; Specific Energy of Nerves, 58, 59 ; localization 
of Sensation, 59-62 ; Subjective Sensations, 62-64. 

Results of Variation of Sensibility : — Rise and fall of Sensibility, 64-67 ; 
Paraesthesia, 67, 68 ; rationale of organically conditioned Elusions, 
68, 69. 

CHAPTEE V. 
illusions of perception — continued, 

A. Passive Illusions (b) as determined by the Environment. 

Exceptional Relation of Stimulus to Organ : — Displacement of organ, etc., 
70-72. 

Exceptional Arrangement of Circumstances in the Environment : — Mis- 
interpretation of the direction and movement of objects, 72—75; 
misperception of Distance, 75, 76 ; Illusions of depth, relief, and 
solidity in Art, 77-81 ; Illusions connected with the perception of 
objects through transparent coloured media, 82-84 ; visual trans- 
formation of concave into convex form, 84-86 ; false recognition of 
objects, 86, 87 ; inattention to Sense-impression in Recognition, 
87-91 ; suggestion taking the direction of familiar recurring ex. 
periences, 91, 92. 

CHAPTEE VI. 

illusions of perception — continued. 

B. Active Illusions. 

Preperception and Elusion, 93-95. 

Voluntary Preperception ; — Choice of interpretation in the case of risible 
movement, 95, 96 ; and in the case of flat projections of form, 
96-98 ; capricious interpretation of obscure impressions, 99, 100. 

Involuntary Preperception : — Effects of permanent Predisposition, 101, 102; 
effects of partial temporary Preadjustment, 102-105; complete Pre« 



CONTENTS. ix 

adjustment or Expectation, 106-109 ; subordination of Sense-impres- 
sion to Preperception, 109-111 ; transition from Illusion to Halluci- 
nation, 111, 112 ; rudimentary Hallucinations, 112-114 ; developed 
Hallucinations, 114-116; Hallucination in normal life, 116, 117; 
Hallucinations of insanity, 118-120 ; gradual development of Sense- 
illusions, and continuity of normal and abnormal life, 120-123 ; 
Sanity and Insanity distinguished, 123-126. 



CHAPTEE VII. 

DKEAMS. 

Mystery of sleep, 127, 128; theories of Dreams, 128, 129; scientific 
explanation of Dreams, 129, 130. 

Sleep and Dreaming : — Condition of organism during sleep, 131, 132; 
Are the nervous centres ever wholly inactive during sleep ? 132—134 
nature of cerebral activity involved in Dreams, 134-136 ; psychical 
conditions of Dreams, 136-138. 

The Bream as Illusion : — External Sense-impressions as excitants of 
Dream-images, 139-143 ; internal " subjective " stimuli in the sense- 
organs, 143-145 ; organic sensations, 145-147 ; how sensations are 
exaggerated in Dream-interpretation, 147-151. 

The Dream as Hallucination : — Results of direct central stimulation 
151-153 ; indirect central stimulation and association, 153-155. 

The Form and Structure of Dreams : — The incoherence of Dreams ex- 
plained, 156-161 ; coherence and unity of Dream as effected (a) by 
coalescence and transformation of images, 161-163 ; (b) by a ground- 
tone of feeling, 164-168 ; (c) by the play of associative dispositions, 
168-172 ; (d) by the activities of selective attention stimulated by 
the rational impulse to connect and to arrange, 172-176 ; examples 
of Dreams, 176-179 ; limits of intelligence and rational activity in 
Dreams, 180-182 ; Dreaming and mental disease, 182, 183 j After- 
dreams and Apparitions, 183-185. 

Note.— The Hypnotic Condition, 185-188. 

CHAPTEE mi. 

ILLUSIONS OF INTROSPECTION. 

Illusions of Introspection defined, 189-192 ; question of the possibility 
of illusory Introspection, 192-194; incomplete grasp of internal 
feelings as such, 194-196 ; misobservation of internal feelings : Pas- 



CONTENTS. 

sive Illusions, 196-199 ; Active Illusions, 199-202 ; malobscrvation of 
subjective states, 202-205 ; Illusory Introspection in psychology and 
philosophy, 205-208 ; value of the Introspective method. 208-211. 



CHAPTEE IX. 

OTHER QTJASI-PRESENTATIVE ILLUSIONS: ERRORS OP INSIGHT. 

'motion and Perception, 212; JEsthetic Intuition, 213; Subjective Im- 
pressions of beauty misinterpreted, 213-216 ; analogous Emotional 
Intuitions, 216, 217 ; Insight, its nature, 217-220 ; Passive Illusions 
of Insight, 220-222 ; Active Illusions of Insight : projection of indi- 
vidual feelings, 222-224 ; the poetic transformation of nature, 224- 
226 ; special predispositions as falsifying Insight, 226-228 ; value of 
faculty of Insight, 228-230. 



CHAPTER X. 

ILLUSIONS OF MEMORY. 

Vulgar confidence in Memory, 231-233 ; definition of Memory, 233-235 ; 
Psychology of Memory, 235-237; Physiology of Memory, 237, 238; 
Memory as localization in the past, 238-241 ; Illusions of Memory 
classified, 241-245. 

(1) Illusions of Time-Perspective : — 

(a) Definite Localization of events : constant errors in retrospective 
estimate of time, 245-249 ; varying errors : estimate of duration 
during a period, 249-251 ; variations in retrospective estimate of 
duration, 251-256. 

(b) Indefinite Localization : effect of vividness of mnemonic image ' 
on the apparent distance of events, 256-258 ; isolated public events, 
258, 259 ; active element in errors of Localization, 259-261. 

(2) Distortions of Memory : — Transformation of past through forgetfnl- 
ness, 261-264 ; confusion of distinct recollections, 264—266 ; Active 
Illusion: influence of present imaginative activity, 266-269 ; exagge- 
ration in recollections of remote experiences, 269, 270; action of 
present feeling in transforming past, 270, 271. 

(3) Hallucinations of Memory : — Their nature, 271-273; past dreams taken 

for external experiences, 273-277 ; past waking imagination taken 
for external reality, 277-280 ; recollection of prenatal ancestral 
experience, 280, 2S1 ; filling up gaps in recollection, 281-283. 



CONTENTS. XI 

Illusions connected with, Personal Identity : — Illusions of Memory and 
Sense of identity, 283, 284 ; idea of permanent self, how built up, 
285-287; disturbances of sense of identity, 287-290; fallibility and 
trustworthiness of Memory, 290-292. 

Note. — Momentary Illusions of Self-consciousness, 293. 



CHAPTEE XI. 

ILLUSIONS OF BELIEF. 

Belief as Immediate or Intuitive, 294-296 ; simple and compound Belief, 
296. 

A. Simple Illusory Belief : — 

(1) Expectation : its nature, 297, 298 ; Is Expectation ever intuitive ? 
298 ; Expectation and Inference from the past, 299-301 ; Expec- 
tation of new kinds of experience, 301, 302 ; Permanent Expecta- 
tions of remote events, 302 ; misrepresentation of future duration, 
302-305 ; Imaginative transformation of future, 305-307. 

(2) Quasi-Expectations : anticipation of extra-personal experiences, 
307, 308 ; Betrospective Beliefs, 30S-312. 

B. Compound Illusory Belief: — 

(1) Bepresentations of permanent things : their structure, 312 ; our 
representations of others as illusory, 312-315 ; our representation 
of ourselves as illusory, 315; Illusion of self-esteem, 316-318; 
genesis of illusory opinion of self, 318-322 ; Illusion in our repre- 
sentations of classes of things, 322, 323 ; and in our views of the 
world as a whole, 323, 324 ; tendency of belief towards divergence, 
325 ; and towards convergence, 326, 327. 



CHAPTEE XII. 

EESULTS. 

Bange of Illusion, 328-330 ; nature and causes of Illusion in general, 
331-334 ; Illusion identical with Fallacy, 334 ; Illusion as abnormal, 
336, 337 ; question of common error, 337-339 ; evolutionist's con- 
ception of error as maladaptation, 339-344; common intuitions 
tested only by philosophy, 344 ; assumptions of science respecting 
external reality, etc., 344-346 ; philosophic investigation of these 
assumptions, 346-348 ; connection between scientific and philosophic 
consideration of Illusion, 348-350 ; correction of Illusion and its 



x " CONTENTS. 



implications, 351, 352 ; Fundamental Intuitions and modern psycho- 
logy, 35., ; psychology as positive science and as philosophy, 353-355 • 
points of resemblance between acknowledged Illusions and Funda! 
mental Intuitions, 355, 356; question of origin, and question of 
validity, 356 357,- attitude of scientific mind towards philosophic 
2^ 357 " 360 ' P <*« iste ^ toitiona must be taken aa true, 



360, 361. 



ILLUSIONS. 

CHAPTER I. 

THE STUDY OF ILLUSION. 

Common sense, knowing nothing of fine distinctions, 
is wont to draw a sharp line between the region of 
illusion and that of sane intelligence. To be the 
victim of an illusion is, in the popular judgment, to 
be excluded from the category of rational men. The 
term at once calls up images of stunted figures with 
ill-developed brains, half-witted creatures, hardly dis- 
tinguishable from the admittedly insane. And this 
way of thinking of illusion and its subjects is strength- 
ened by one of the characteristic sentiments of our 
age. The nineteenth century intelligence plumes 
itself on having got at the bottom of mediasval visions 
and church miracles, and it is wont to commiserate 
the feeble minds that are still subject to these self- 
deceptions. 

According to this view, illusion is something essen- 
tially abnormal and allied to insanity. And it would 
seem to follow that its nature and origin can be best 



2 THE STUDY OF ILLUSION. 

studied by those whose speciality it is to observe the 
phenomena of abnormal life. Scientific procedure has 
in the main conformed to this distinction of common 
sense. The phenomena of illusion have ordinarily been 
investigated by alienists, that is to say, physicians who 
are brought face to face with their most striking forms 
in the mentally deranged. 

While there are very good reasons for this treat- 
ment of illusion as a branch of mental pathology, 
it is by no means certain that it can be a complete 
and exhaustive one. Notwithstanding the flattering 
supposition of common sense, that illusion is essentially 
an incident in abnormal life, the careful observer knows 
well enough that the case is far otherwise. 

There is, indeed, a view of our race diametrically 
opposed to the flattering opinion referred to above, 
namely, the humiliating judgment that all men 
habitually err, or that illusion is to be regarded as 
the natural condition of mortals. This idea has found 
expression, not only in the cynical exclamation of the 
misanthropist that most men are fools, but also in the 
cry of despair that sometimes breaks from the weary 
searcher after absolute truth, and from the poet when 
impressed with the unreality of his early ideals. 

Without adopting this very disparaging opinion 
of the intellectual condition of mankind, we must 
recognize the fact that most men are sometimes 
liable to illusion. Hardly anybody is always con- 
sistently sober and rational in his perceptions and 
beliefs. A momentary fatigue of the nerves, a little 
mental excitement, a relaxation of the effort of atten- 
tion by which we continually take our bearings with 



POPULAR IDEA OF ILLUSION. 3 

respect to the real world about us, will produce just 
the same kind of confusion of reality and phantasm 
which we observe in the insane. To give but an 
example : the play of fancy which leads to a detection 
of animal and other forms in clouds, is known to be an 
occupation of the insane, and is rightly made use of by 
Shakespeare as a mark of incipient mental aberration 
in Hamlet ; and yet this very same occupation is quite 
natural to children, and to imaginative adults when they 
choose to throw the reins on the neck of their phantasy. 
Our luminous circle of rational perception is surrounded 
by a misty penumbra of illusion. Common sense 
itself may be said to admit this, since the greatest 
stickler for the enlightenment of our age will be found 
in practice to accuse most of his acquaintance at 
some time or another of falling into illusion. 

If illusion thus has its roots in ordinary mental life, 
the study of it would seem to belong to the physiology 
as much as to the pathology of mind. We may even 
go further, and say that in the analysis and explana- 
tion of illusion the psychologist may be expected to 
do more than the physician. If, on the one hand, the 
latter has the great privilege of observing the pheno- 
mena in their highest intensity, on the other hand, the 
former has the advantage of being familiar with the 
normal intellectual process which all illusion simulates 
or caricatures. To, this it must be added that the 
physician is naturally disposed to look at illusion 
mainly, if not exclusively, on its practical side, that 
is, as a concomitant and symptom of cerebral disease, 
which it is needful to be able to recognize. The 
psychologist has a different interest in the subject, 



4 THE STUDY OF ILLUSION. 

being specially concerned to understand the mental 
antecedents of illusion and its relation to accurate 
perception and belief. It is pretty evident, indeed, 
that the phenomena of illusion form a region common 
to the psychologist and the mental pathologist, and 
that the complete elucidation of the subject will need 
the co-operation of the two classes of investigator. 

In the present volume an attempt will be made to 
work out the psychological side of the subject ; that 
is to say, illusions will be viewed in their relation to 
the process of just and accurate perception. In the 
carrying out of this plan our principal attention will 
be given to the manifestations of the illusory impulse 
in normal life. At the same time, though no special 
acquaintance with the pathology of the subject will be 
laid claim to, frequent references will be made to the 
illusions of the insane. Indeed, it will be found that 
the two groups of phenomena — the illusions of the 
normal and of the abnormal condition — are so similar, 
and pass into one another by such insensible grada- 
tions, that it is impossible to discuss the one apart 
from the other. The view of illusion which will be 
adopted in this work is that it constitutes a kind of 
borderland between perfectly sane and vigorous mental 
life and dementia. 

And here at once there forces itself on our atten- 
tion the question, What exactly is to be understood by 
the term " illusion " ? In scientific works treating of 
the pathology of the subject, the word is confined to 
what are specially known as illusions of the senses, 
that is to say, to false or illusory perceptions. And 
there is very good reason for this limitation, since such 



WHAT IS ILLUSION ? 5 

illusions of the senses are the most palpable and 
striking symptoms of mental disease. In addition to 
this, it must be allowed that, to the ordinary reader, 
the term first of all calls up this same idea of a decep- 
tion of the senses. 

At the same time, popular usage has long since 
extended the term so as to include under it errors 
which do not counterfeit actual perceptions. We 
commonly speak of a man being under an illusion 
respecting himself when he has a ridiculously exag- 
gerated view of his own importance, and in a similar 
way of a person being in a state of illusion with 
respect to the past when, through frailty of memory, 
he pictures it quite otherwise than it is certainly 
known to have been. 

It will be found, I think, that there is a very good 
reason for this popular extension of the term. The 
errors just alluded to have this in common with 
illusions of sense, that they simulate the form of 
immediate or self-evident cognition. An idea held 
respecting ourselves or respecting our past history 
does not depend on any other piece of knowledge ; in 
other words, is not adopted as the result of a process 
of reasoning. What I believe with reference to my 
past history, so far as I can myself recall it, I believe 
instantaneously and immediately, without the inter- 
vention of any premise or reason. Similarly, our 
notions of ourselves are, for the most part, obtained 
apart from any process of inference. The view which 
a man takes of his own character or claims on society 
he is popularly supposed to receive intuitively by a 
mere act of internal observation. Such beliefs may 



6 THE STUDY OF ILLUSION. 

not, indeed, have all the overpowering force which 
belongs to illusory perceptions, for the intuition of 
something by the senses is commonly looked on as the 
most immediate and irresistible kind of knowledge. 
Still, they must be said to come very near illusions of 
sense in the degree of their self-evident certainty. 

Taking this view of illusion, we may provisionally 
define it as any species of error which counterfeits the 
form of immediate, self-evident, or intuitive knowledge, 
whether as sense-perception or otherwise. Whenever 
a thing is believed on its own evidence and not as a 
conclusion from something else, and the thing then 
believed is demonstrably wrong, there is an illusion. 
The term would thus appear to cover all varieties of 
error which are not recognized as fallacies or false 
inferences. If for the present we roughly divide all 
our knowledge into the two regions of primary or 
intuitive, and secondary or inferential knowledge, we 
see that illusion is false or spurious knowledge of the 
first kind, fallacy false or spurious knowledge of the 
second kind. At the same time, it is to be remembered 
that this division is only a very rough one. As will 
appear in the course of our investigation, the same 
error may be called either a fallacy or an illusion, 
according as we are thinking of its original mode of 
production or of the form which it finally assumes ; 
and a thorough-going psychological analysis of error 
may discover that these two classes are at bottom very 
similar. 

As we proceed, we shall, I think, find an ample 
justification for our definition. We shall see that 
such illusions as those respecting ourselves or the 



DEFINITION OF ILLUSION. 7 

past arise by very much the same mental processes as 
those which are discoverable in the production of 
illusory perceptions ; and thus a complete psychology 
of the one class will, at the same time, contain the 
explanation of the other classes. 

The reader is doubtless aware that philosophers 
have still further extended the idea of illusion by 
seeking to bring under it beliefs which the common 
sense of mankind has always adopted and never begun 
to suspect. Thus, according to the idealist, the popu- 
lar notion (the existence of which Berkeley, however, 
denied) of an external world, existing in itself and in 
no wise dependent on our perceptions of it, resolves 
itself into a grand illusion of sense. 

At the close of our study of illusions we shall 
return to this point. We shall there inquire into the 
connection between those illusions which are popularly 
recognized as such, and those which first come into 
view or appear to do so (for we must not yet assume 
that there are such) after a certain kind of philosophic 
reflection. And some attempt will be made to de- 
termine roughly how far the process of dissolving these 
substantial beliefs of mankind into airy phantasms 
may venture to go. 

For the present, however, these so-called illusions 
in philosophy will be ignored. It is plain that illusion 
exists only in antithesis to real knowledge. This last 
must be assumed as something above all question. 
And a rough and provisional, though for our purpose 
sufficiently accurate, demarcation of the regions of the 
real and the illusory seems to coincide with the line 
which common sense draws between what all normal 



8 THE STUDY OF ILLUSION. 

men agree in holding and what the individual holds, 
whether temporarily or permanently, in contradiction 
to this. For our present purpose the real is that 
which is true for all. Thus, though physical science 
may tell us that there is nothing corresponding to our 
sensations of colour in the world of matter and motion 
which it conceives as surrounding us; yet, inasmuch 
as to all men endowed with the normal colour-sense 
the same material objects appear to have the same 
colour, we may speak of any such perception as 
practically true, marking it off from those plainly 
illusory perceptions which are due to some subjective 
cause, as, for example, fatigue of the retina. 

To sum up : in treating of illusions we shall 
assume, what science as distinguished from philosophy 
is bound to assume, namely, that human experience is 
consistent ; that men's perceptions and beliefs fall into 
a consensus. From this point of view illusion is seen 
to arise through some exceptional feature in the situa- 
tion or condition of the individual, which, for tho 
time, breaks the chain of intellectual solidarity which 
under ordinary circumstances binds the single member 
to the collective body. Whether the common ex- 
perience which men thus obtain is rightly interpreted 
is a question which does not concern us here. For our 
present purpose, which is the determination and 
explanation of illusion as popularly understood, it is 
sufficient that there is this general consensus of belief, 
and this may provisionally be regarded as at least 
practically true. 



CHAPTEE II. 

THE CLASSIFICATION OF ILLUSIONS. 

If illusion is the simulation of immediate knowledge, 
the most obvious mode of classifying illusions would 
appear to be according to the variety of the knowledge 
which they simulate. 

Now, the popular psychology that floats about in 
thf ordinary forms of language has long since dis- 
tinguished certain kinds of unreasoned or uninferred 
knowledge. Of these the two best known are per- 
ception and memory. When I see an object before 
me, or when I recall an event in my past experience, 
I am supposed to grasp a piece of knowledge directly, 
to know something immediately, and not through the 
medium of something else. Yet I know differently in 
the two cases. In the first I know by what is called a 
presentative process, namely, that of sense-perception ; 
in the second I know by a representative process, 
namely, that of reproduction, or on the evidence of 
memory. In the one case the object of cognition is 
present to my perceptive faculties ; in the other it 
is recalled by the power of memory. 

Scientific psychology tends, no doubt, to break down 
some of these popular distinctions. Just as the zoologist 



10 THE CLASSIFICATION OF ILLUSIONS. 

sometimes groups together varieties of animals which 
the unscientific eye would never think of connecting, so 
the psychologist may analyze mental operations which 
appear widely dissimilar to the popular mind, and 
reduce them to one fundamental process. Thus recent 
psychology draws no sharp distinction between per- 
ception and recollection. It finds in both very much 
the same elements, though combined in a different way 
Strictly speaking, indeed, perception must be defined 
as a presentative-representative operation. To the 
psychologist it conies to very much the same thing 
whether, for example, on a visit to Switzerland, our 
minds are occupied in perceiving the distance of a 
mountain or in remembering some pleasant excursion 
which we made to it on a former visit. In both cases 
there is a reinstatement of the past, a reproduction 
of earlier experience, a process of adding to a present 
impression a product of imagination — taking this word 
in its widest sense. In both cases the same laws of 
reproduction or association are illustrated. 

Just as a deep and exhaustive analysis of the 
intellectual operations thus tends to identify their 
various forms as they are distinguished by the popular 
mind, so a thorough investigation of the flaw's in these 
operations, that is to say, the counterfeits of knowledge, 
will probably lead to an identification of the essential 
mental process which underlies them. It is apparenr, 
for example, that, whether a man projects some figment, 
of his imagination into the external world, giving it, 
present material reality, or whether (if I may be 
allowed the term) he retrojects it into the dim region 
of the past, and takes it for a realitv that has been 



POPULAR AND SCIENTIFIC CLASSIFICATION. 11 

he is committing substantially the same blunder. 
The source of the illusion in both cases is one and 
the same. 

It might seem to follow from this that a scientific 
discussion of the subject would overlook the obvious 
distinction between illusions of perception and those of 
memory ; that it would attend simply to differences in 
the mode of origination of the illusion, whatever its 
external form. Our next step, then, would appear to 
be to determine these differences in the mode of pro- 
duction. 

That there are differences in the origin and source 
of illusion is a fact which has been fully recognized by 
those writers who have made a special study of sense- 
illusions. By these the term illusion is commonly 
employed in a narrow, technical sense, and opposed 
to hallucination. An illusion, it is said, must always 
have its starting-point in some actual impression, 
whereas a hallucination has no such basis. Thus it is 
an illusion when a man, under the action of terror, 
takes a stump of a tree, whitened by the moon's rays, 
for a ghost. It is a hallucination when an imaginative 
person so vividly pictures to himself the form of 
some absent friend that, for the moment, he fancies 
himself actually beholding him. Illusion is thus a 
partial displacement of external fact by a fiction of the 
imagination, while hallucination is a total displacement. 

This distinction, which has been adopted by the 
majority of recent alienists, 1 is a valuable one, and 

1 A history of the distinction is given by Brierre de Boismont, in 
his work On Illusions (translated by R. T. Hulme, 1859). He saya 
that Arnold (1806) first defined hallucination, and distinguished it 



12 THE CLASSIFICATION OF ILLUSIONS. 

must not be lost sight of here. It would seem, from 
a psychological point of view, to be an important cir- 
cumstance in the genesis of a false perception whether 
the intellectual process sets out from within or from 
without. And it will be found, moreover, that this 
distinction may be applied to all the varieties of error 
which I propose to consider. Thus, for example, it will 
be seen further on that a false recollection may set out 
either from the idea of some actual past occurrence or 
from a present product of the imagination. 

It is to be observed, however, that the line of 
separation between illusion and hallucination, as thus 
defined, is a very narrow one. In by far the largest 
number of hallucinations it is impossible to prove that 
there is no modicum of external agency co-operating 
in the production of the effect. It is presumable, 
indeed, that many, if not all, hallucinations have such 
a basis of fact. Thus, the madman who projects his 
internal thoughts outwards in the shape of external 
voices may, for aught we know, be prompted to do so 
in part by faint impressions coming from the ear, the 
result of those slight stimulations to which the organ 
is always exposed, even in profound silence, and which 
in his case assume an exaggerated intensity. And ever 
if it is clearly made out that there are hallucinations 
in the strict sense, that is to say, false perceptions 
Avhich are wholly due to internal causes, it must be 
conceded that illusion shades off into hallucination by 
steps which it is impossible for science to mark. In 

from illusion. Esquirer, in his work, Des Maladies Mentales (1838), 
may bo said to have fixed the distinction. (See Hunt's translation* 
1845, p. 111.) 



ILLUSION AND HALLUCINATION. 13 

many cases it must be left an open question whether 
the error is to be classed as an illusiun or as a hallu- 
cination. 1 

For these reasons, I think it best not to make the 
distinction between illusion and hallucination the 
leading principle of my classification. However im- 
portant psychologically, it does not lend itself to this 
purpose. The distinction must be kept in view and 
illustrated as far as possible. Accordingly, while in 
general following popular usage and employing the 
term illusion as the generic name, I shall, when con- 
venient, recognize the narrow and technical sense of 
the term as answering to a species co-ordinate with 
hallucination. 

Departing, then, from what might seem the ideally 
best order of exposition, I propose, after all, to set 
out with the simple popular scheme of faculties already 
referred to. Even if they are, psychologically con- 
sidered, identical operations, perception and memory 
are in general sufficiently marked off by a speciality 
in the form of the operation. Thus, while memory is 
the reproduction of something with a special reference 
of consciousness to its past existence, perception is the 
reproduction of something with a special reference to 
its present existence as a part of the presented object. 
In other words, though largely representative when 
viewed as to its origin, perception is preventative in 
relation to the object which is supposed to be im- 

1 This fact has been fully recognized by writers on the pathology 
of the subject; for example, Griesinger, Mental Patholagy and Thera- 
peutics (Loudon, 1867), p. 84; Baillarger, article, "Des Hallucina- 
tions," in the Mdmoires de VAcade'mie lioyale de Me'decine, torn. sii. 
p. 273, etc. ; Wundt, Physiologische Psychologie, p. 653. 



14 THE CLASSIFICATION OF ILLUSIONS. 

mediately present to the mind at the moment. 1 
Hence the convenience of recognizing the popular 
classification, and of making it our starting-point in 
the present case. 

All knowledge which has any appearance of being 
directly reached, immediate, or self-evident, that is 
to say, of not being inferred from other knowledge, 
may be divided into four principal varieties : Internal 
Perception or Introspection of the mind's own feelings ; 
External Perception ; Memory ; and Belief, in so far as 
it simulates the form of direct knowledge. The first 
is illustrated in a man's consciousness of a present 
feeling of pain or pleasure. The second and the third 
kinds have already been spoken of, and are too familiar 
to require illustration. It is only needful to remark 
here that, under perception, or rather in close con- 
junction with it, I purpose dealing with the knowledge 
of other's feelings, in so far as this assumes the aspect 
of immediate knowledge. The term belief is here 
used to include expectations and any other kinds of 
conviction that do not fall under one of the other 
heads. An instance of a seemingly immediate belief 
would be a prophetic prevision of a coming disaster, 
or a man's unreasoned persuasion as to his own powers 
of performing a difficult task. 

It is, indeed, said by many thinkers that there are 
no legitimate immediate beliefs ; that all our expecta- 
tions and other convictions about things, in so far as they 
are sound, must repose on other genuinely immediate 

1 I here touch on the distinction between the psychological and 
the philosophical view of perception, to be brought out more fully 
by-and-by. 



VARIETIES OF IMMEDIATE KNOWLEDGE. 15 

knowledge, more particularly sense-perception and 
memory. This difficult question need not be discussed 
here. It is allowed by all that there is a multitude of 
beliefs which we hold tenaciously and on which we 
are ready to act, which, to the mature mind, wear the 
appearance of intuitive truths, owing their cogency to 
nothing beyond themselves. A man's belief in his 
own merits, however it may have been first obtained, is 
as immediately assured to him as his recognition of a 
real object in the act of sense-perception. It may be 
added that many of our every-day working beliefs 
about the world in which we live, though presumably 
derived from memory and perception, tend to lose all 
traces of their origin, and to simulate the aspect of 
intuitions. Thus the proposition that logicians are in 
the habit of pressing on our attention, that " Men are 
mortal," seems, on the face of it, to common sense to be 
something very like a self-evident truth, not depend- 
ing on any particular facts of experience. 

In calling these four forms of cognition immediate, 
I must not, however, be supposed to be placing them on 
the same logical level. It is plain, indeed, to a reflec- 
tive mind that, though each may be called immediate 
in this superficial sense, there are perceptible differences 
in the degree of their immediacy. Thus it is manifest, 
after a moment's reflection, that expectation, so far 
as it is just, is not primarily immediate in the sense 
in which purely presentative knowledge is so, since it 
can be shown to follow from something else. So a 
general proposition, though through familiarity and 
innumerable illustrations it has acquired a self-evident 
character, is seen with a very little inspection to be 



16 THE CLASSIFICATION OF ILLUSIONS. 

less fundamentally and essentially so than the proposi- 
tion, " I am now feeling pain ; " and it will be found 
that even with respect to memory, when the remem- 
bered event is at all remote, the process of cognition 
approximates to a mediate operation, namely, one of 
inference. What the relative values of these different 
kinds of immediate knowledge are is a point which 
will have to be touched on at the end of our study. 
Here it must suffice to warn the reader against the 
supposition that this value is assumed to be identical. 

It might seem at a first glance to follow from this 
four-fold scheme of immediate or quasi-immediate 
knowledge that there are four varieties of illusion. 
And this is true in the sense that these four heads 
cover all the main varieties of illusion. If there are 
only four varieties of knowledge which can lay any 
claim to be considered immediate, it must be that 
every illusion will simulate the form of one of these 
varieties, and so be referable to the corresponding- 
division. 

But though there are conceivably these four species 
of illusion, it does not follow that there are any actual 
instances of each class forthcoming. This we cannot 
determine till we have investigated the nature and 
origin of illusory error. For example, it might be 
found that introspection, or the immediate inspection 
of our own feelings or mental states, does not supply 
the conditions necessary to the production of such 
error. And, indeed, it is probable that most persons, 
antecedently to inquiry, would be disposed to say that 
to fall into error in the observation of what is actually 
going on in our own minds is impossible. 



VARIETIES OF ILLUSION. 17 

With the exception of this first division, however, 
this scheme may easily be seen to answer to actual 
phenomena. That there are illusions of perception is 
obvious, since it is to the errors of sense that the term 
illusion has most frequently been confined. It is 
hardly less evident that there are illusions of memory. 
The peculiar difficulty of distinguishing between a 
past real event and a mere phantom of the imagina- 
tion, illustrated in the exclamation, " I either saw it 
or dreamt it," sufficiently shows that memory is liable 
to be imposed on. Finally, it is agreed on by all that 
the beliefs we are wont to regard as self-evident are 
sometimes erroneous. When, for example, an imagina- 
tive woman says she knows, by mere intuition, that 
something interesting is going to happen, say the 
arrival of a favourite friend, she is plainly running 
the risk of being self-deluded. So, too, a man's esti- 
mate of himself, however valid for him, may turn out 
to be flagrantly false. 

In .the following discussion of the subject I shall 
depart from the above order in so far as to set out with 
illusions of sense-perception. These are well ascer- 
tained, forming, indeed, the best-marked variety. 
And the explanation of these has been carried much 
further than that of the others. Hence, according to 
the rule to proceed from the known to the unknown, 
there will be an obvious convenience in examining 
these first of all. After having done this, we shall be 
in a position to inquire whether there is anything 
analogous in the region of introspection or internal 
perception. Our study of the errors of sense-per- 
ception will, moreover, prove the best preparation for 



18 THE CLASSIFICATION OF ILLUSIONS. 

an inquiry into the nature and mode of production of 
the remaining two varieties. 1 

I would add that, in close connection with the 
first division, illusions of perception, I shall treat the 
subtle and complicated phenomena of dreams. A1-' 
though containing elements which ought, according to 
strictness, to be brought under one of the other heads, 
they are, as their common appellation, "visions," shows, 
largely simulations of external, and more especially 
visual, perception. 

Dreams are no doubt sharply marked off from 
illusions of sense-perception by a number of special 
circumstances. Indeed, it may be thought that they 
cannot be adequately treated in a work that aims 
primarily at investigating the illusions of normal life, 
and should rather be left to those who make the 
pathological side of the subject their special study. 
Yet it may, perhaps, be said that in a wide sense 
dreams are a* feature of normal life. And, however 
this be, they have quite enough in common with othei 
illusions of perception to justify us in dealing with 
them in close connection with these. 

1 It might even be urged that the order here adopted is scientifically 
the best, since sense-perception is the earliest form of knowledge, 
introspected facts being known only in relation to perceived facts. 
But if the mind's knowledge of its own states is thus later in time, it is 
earlier in the logical order, that is to say, it is the most strictly pre- 
sentative form of knowledge. 



CHAPTER III. 

ILLUSIONS OF PERCEPTION : GENERAL. 

The errors with which we shall be concerned in this 
chapter are those which are commonly denoted by the 
term illusion, that is to say, those of sense. They 
are sometimes called deceptions of the senses ; but 
this is a somewhat loose expression, suggesting that 
we can be deceived as to sensation itself, though, as we 
shall see later on, this is only true in a very restricted 
meaning of the phrase. To speak correctly, sense- 
illusions must be said to arise by a simulation of the 
form of just and accurate perceptions. Accordingly, 
we shall most frequently speak of them as illusions of 
perception. 

In order to investigate the nature of any kind of 
error, it is needful to understand the kind of know- 
ledge it imitates, and so we must begin our inquiry 
into the nature of illusions of sense by a brief account 
of the psychology of perception ; and, in doing this, 
we shall proceed best by regarding this operation 
in its most complete form, namely, that of visual per- 
ception. 

I may observe that in this analysis of perception I 
shall endeavour to keep to known facts, namely, the 



20 ILLUSIONS OF PERCEPTION. 

psychical phenomena or events which can be seen by 
the methods of scientific psychology to enter into the 
mental content called the percept. I do not now 
inquire whether such an analysis can help us to under- 
stand all that is meant by perception. This point will 
have to be touched later on. Here it is enough to say 
that, whatever our philosophy of perception may be, 
we must accept the psychological fact that the con- 
crete mental state in the act of perception is built up 
out of elements, the history of which can be traced by 
the methods of mental science. 

Psychology of Perception. 

Confining ourselves for the present to the mental, 
as distinguished from the physical, side of the opera- 
tion, we soon find that perception is not so simple a 
matter as it might at first seem to be. When a man 
on a hot day looks at a running stream and " sees " 
the delicious coolness, it is not difficult to show that 
he is really performing an act of mental synthesis, 
or imaginative construction. To the sense-impression x 
which his eye now gives him, he adds something 
which past experience has bequeathed to his mind. 
In perception, the material of sensation is acted on 
by the mind, which embodies in its present attitude 
all the results of its past growth. Let us look at this 
process of synthesis a little more closely. 

When a sensation arises in the mind, it may, under 

1 Here and elsewhere I use the word " impression " for the whole 
complex of sensation which is present at the moment. It may, 
perhaps, not be unnecessary to add that, in employing this term, I am 
making no assumption about the independent existence of external 
objects. 



PSYCHOLOGY OF PERCEPTION. 21 

certain circumstances, go unattended to. In that case 
there is no perception. The sensation floats in the 
dim outer regions of consciousness as a vague feeling, 
the real nature and history of which are unknown. 
This remark applies' not only to the undefined bodily 
sensations that are always oscillating about the 
threshold of obscure consciousness, but to the higher 
sensations connected with the special organs of per- 
ception. The student in optics soon makes the start- 
ling discovery that his field of vision has all through 
his life been haunted with weird shapes which have 
never troubled the serenity of his mind just because 
they have never been distinctly attended to. 

The immediate result of this process of directing 
the keen glance of attention to a sensation is to give 
it greater force and distinctness. By attending to it we 
discriminate it from other feelings present and past, 
and classify it with like sensations previously received. 
Thus, if I receive a visual impression of the colour 
orange, the first consequence of attending to it is to 
mark it off from other colour-impressions, including 
those of red and yellow. And in recognizing the 
peculiar quality of the impression by applying to it 
the term orange, I obviously connect it with other 
similar sensations called by the same name. If a sen- 
sation is perfectly new, there cannot, of course, be this 
process of classifying, and in this case the closely 
related operation of discriminating it from other sen- 
sations is less exactly performed. But it is hardly 
necessary to remark that, in the mind of the adult, 
under ordinary circumstances, no perfectly new sensa- 
tion ever occurs. 



22 ILLUSIONS OF PERCEPTION. 

When the sensation, or complex sensation, is 
thus defined and recognized, there follows the process 
of interpretation, by which I mean the taking up of 
the impression as an element into the complex mental 
state known as a percept. Without going into the 
philosophical question of what this process of synthesis 
exactly means, I may observe that, by common con- 
sent, it takes place to a large extent by help of a 
reproduction of sensations of various kinds experi- 
enced in the past. That is to say, the details in this 
act of combination are drawn from the store of mental 
recollections to which the growing mind is ever adding. 
In other words, the percept arises through a fusion of 
an actual sensation with mental representations or 
" images " of sensation. 1 Every element of the object 
that we thus take up in the act of perception, or put 
into the percept, as its actual size, distance, and so on, 
will be found to make itself known to us through 
mental images or revivals of past experiences, such as 
those we have in handling the object, moving to and 
from it, etc. It follows that if this is an essential 
ingredient in the act of perception, the process closely 
resembles an act of inference ; and, indeed, Helmholtz 
distinctly calls the perception of distance an uncon- 

1 Psychological usage has now pretty well substituted the term 
" image " for " idea," in order to indicate an individual (as distinguished 
from a general) representation of a sensation or percept. It might, 
perhaps, be desirable to go further in this process of differentiating 
language, and to distinguish between a sensational image, e.g. the 
representation of a colour, and a perceptional -image, as the represen- 
tation of a coloured object. It may be well to add that, in speaking 
of a fusion of an image and a sensation, I do not mean that the former 
exists apart for a single instant. The term " fusion " is used figura- 
tively to describe the union of the two sides or aspects of a complete 
percept. 



PERCEPTION AS INTERPRETATION. 23 

scious inference or a mechanically performed act of 
judgment. 

I have hinted that these recovered sensations 
include the feelings we experience in connection with 
muscular activity, as in moving our limbs, resisting or 
lifting heavy bodies, and walking to a distant object. 
Modern psychology refers the eye's instantaneous 
recognition of the most important elements of an 
object (its essential or " primary " qualities) to a rein- 
statement of such simple experiences as these. It is, 
indeed, these reproductions which are supposed to con- 
stitute the substantial background of our percepts. 

Another thing worth noting with respect to this 
process of filling up a sense-impression is that it draws 
on past sensations of the eye itself. Thus, when I 
look at the figure of an acquaintance from behind, 
my reproductive visual imagination supplies a repre- 
sentation of the impressions I am wont to receive 
when the more interesting aspect of the object, the 
front view, is present to my visual sense. 1 

We may distinguish between different steps in the 
full act of visual recognition. First of all comes the 
construction of a material object of a particular figure 
and size, and at a particular distance ; that is to say, 
the recognition of a tangible thing having certain 
simple space-properties, and holding a certain relation 
to other objects, and more especially our own body, in 
space. This is the bare perception of an object, which 
always takes place even in the case of perfectly new 

1 This impulse to fill in visual elements not actually present is 
strikingly illustrated in people's difficulty in recognizing the gap in 
the field of vision answering to the insensitive " blind " spot on the 
tetina. (See Helmholtz, Physiologische Optik, p. 573, et seq.) 



24 ILLUSIONS OF PEKCEPTION. 

objects, provided they are seen with any degree of 
distinctness. It is to be added that the reference of a 
sensation of light or colour to such an object involves 
the inclusion of a quality answering to the sensation, 
as brightness, or blue colour, in the thing thus intuited. 

This part of the process of filling in, which is the 
most instantaneous, automatic, and unconscious, may 
be supposed to answer to the most constant and there- 
fore the most deeply organized connections of ex- 
perience ; for, speaking generally, we never have an 
impression of colour, except when there are circum- 
stances present which • are fitted to yield us those 
simple muscular and tactual experiences through 
which the ideas of a particular form, size, etc., are 
pretty certainly obtained. 

The second step in this process of presentative 
construction is the recognition of an object as one of 
a class of things, for example, oranges, having certain 
special qualities, as a particular taste. In this step the 
connections of experience are less deeply organized, and 
so we are able to some extent, by reflection, to recognize, 
it as a kind of intellectual working up of the materials 
supplied us by the past. It is to be noted that this 
process of recognition involves a compound operation 
of classifying impressions as distinguished from that 
simple operation by which a single impression, such as 
a particular colour, is known. Thus the recognition of 
such an object as an orange takes place by a rapid 
classing of a multitude of passive sensations of colour, 
light, and shade, and those active or muscular sensa- 
tions which are supposed to enter into the visual per- 
ception of form. 



PERCEPTION AS RECOGNITION. 25 

A still less automatic step in the process of visual 
recognition is that of identifying individual objects, as 
Westminster Abbey, or a friend, John Smith. The 
amount of experience that is here reproduced may be 
very large, as in the case of recognizing a person with 
whom we have had a long and intimate acquaintance. 

If the recognition of an object as one of a class, 
for example, an orange, involves a compound process 
of classing impressions, that of an individual object 
involves a still more complicated process. The identifi- 
cation of a friend, simple as this operation may at first 
appear, really takes place by a rapid classing of all the 
salient characteristic features which serve as the visible 
marks of that particular person. 

It is to be noted that each kind of recognition, 
specific and individual, takes place by a consciousness 
of likeness amid unlikeness. It is obvious that a new 
individual object has characters not shared in by other 
objects previously inspected. Thus, we at once class 
a man with a dark-brown skin, wearing a particular 
garb, as a Hindoo, though he may differ in a host of 
particulars from the other Hindoos that we have ob- 
served. In thus instantly recognizing him as a 
Hindoo, we must, it is plain, attend to the points of 
similarity, and overlook for the instant the points of 
dissimilarity. In the case of individual identification, 
the same thing happens. Strictly speaking, no object 
ever appears exactly the same to us on two occasions. 
Apart from changes in the object itself, especially in the 
case of living beings, there are varying effects of illumi- 
nation, of position in relation to the eye, of distance, and 
so on, which very distinctly affect the visual impression 



26 ILLUSIONS OF PERCEPTION. 

at different times. Yet the fact of our instantly recog- 
nizing a familiar object in spite of these fluctuations 
of appearance, proves that we are able to overlook a 
very considerable amount of diversity when a certain 
amount of likeness is present. 

It is further to be observed that in these last stages 
of perception we approach the boundary line between 
perception and inference. To recognize an object as 
one of a class is often a matter of conscious reflection 
and judgment, even when the class is constituted by 
obvious material qualities which the senses may be 
supposed to apprehend immediately. Still more 
clearly does perception pass into inference when the 
class is constituted by less obvious qualities, which 
require a careful and prolonged process of recollection, 
discrimination, and comparison, for their recognition. 
Thus, to recognize a man by certain marks of gesture 
and manner as a military man or a Frenchman, though 
popularly called a perception, is much more of an 
unfolded process of conscious inference. And what 
applies to specific recognition applies still more forcibly 
to individual recognition, which is often a matter of 
very delicate conscious comparison and judgment. To 
say where the line should be drawn here between per- 
ception and observation on the one hand, and inference 
on the other, is clearly impossible. Our whole study of 
the illusions of perception will serve to show that the 
one shades oft into the other too gradually to allow of 
our drawing a hard and fast line between them. 

Finally, it is to be noted that these last stages of 
perception bring us near the boundary line which 
separates objective experience as common and universal, 



PERCEPTION AND INFERENCE. 27 

and subjective or variable experience as confined to one 
or to a few. In the bringing of the object under a certain 
class of objects there is clearly room for greater variety 
of individual perception. For example, the ability to 
recognize a man as a Frenchman turns on a special kind 
of previous experience. And this transition from the 
common or universal to the individual experience is seen 
yet more plainly in the case of individual recognition. 
To identify an object, say a particular person, com- 
monly presupposes some previous experience or know- 
ledge of this object, and the existence in the past of 
some special relation of the recognizer to the recog- 
nized, if only that of an observer. In fact, it is evident 
that in this mode of recognition we have the transition 
from common perception to individual recollection. 1 

While we may thus distinguish different steps in 
the process of visual recognition, we may make a 
further distinction, marking off a passive and an active 
stage in the process. The one may be called the stage 
of preperception, the other that of perception proper. 2 
In the first the mind holds itself in a passive 
attitude, except in so far as the energies of external 
attention are involved. The impression here awakens 
the mental images which answer to past experiences 
according to the well-known laws of association. The 
interpretative image which is to transform the impres- 

1 This relation will be more fully discussed under the head of 
" Memory." 

2 I adopt this distinction from Dr. J. Hughlings Jackson. See 
his articles, " On Affections of Speech from Diseases of the Brain," in 
Brain, Nos. iii. and vii. The second stage might conveniently be 
named apperception, but for the special philosophical associations of 
the term. 



28 ILLUSIONS OF PERCEPTION. 

sion into a percept is now being formed by a mere 
process of suggestion. 

When the image is thus formed, the mind may be 
said to enter upon a more active stage, in which it now 
views the impression through the image, or applies 
this as a kind of mould or framework to the impres- 
sion. This appears to involve an intensification of the 
mental image, transforming it from a representative 
to a presentative mental state, making it approxi- 
mate somewhat to the full intensity of the sensation. 
In many of our instantaneous perceptions these two 
stages are indistinguishable to consciousness. Thus, in 
most cases, the recognition of size, distance, etc., takes 
place so rapidly that it is impossible to detect the 
two phases here separated. But in the classification 
of an object, or the identification of an individual 
thing, there is often an appreciable interval between 
the first reception of the impression and the final 
stage of complete recognition. And here it is easy to 
distinguish the two stages of preperception and per- 
ception. The interpretative image is slowly built up 
by the operation of suggestion, at the close of which 
the impression is suddenly illumined as by a flash of 
light, and takes a definite, precise shape. 

Now, it is to be noted that the process of preper- 
ception will be greatly aided by any circumstance that 
facilitates the construction of the particular interpre- 
tative image required. Thus, the more frequently a 
similar process of perception has been performed in 
the past, the more ready will the mind be to fall into 
the particular way of interpreting the impression. As 
G. H. Lewes well remarks, " The artist sees details 



PKEPEEOEPTION. 29 

where to other eyes there is a vague or confused mass ; 
the naturalist sees an animal where the ordinary eye 
only sees a form." 1 This is but one illustration of the 
seemingly universal mental law, that what is repeatedly 
done will be done more and more easily. 

The process of preperception may be shortened, not 
only by means of a permanent disposition to frame the 
required interpretative scheme, the residuum of past 
like processes, but also by means of any temporary dis- 
position pointing in the same direction. If, for 
example, the mind of a naturalist has just been occu- 
pied about a certain class of bird, that is to say, if he 
has been dwelling on the mental image of this bird, he 
will recognize one at a distance more quickly than 
he would otherwise have done. Such a simple mental 
operation as the recognition of one of the less common 
flowers, say a particular orchid, will vary in duration 
according as we have or have not been recently forming 
an image of this flower. The obvious explanation of 
this is that the mental image of an object bears a very 
close resemblance to the corresponding percept, differ- 
ing from it, indeed, in degree only, that is to say, 
through the fact that it involves no actual sensation. 
Here again we see illustrated a general psychological 
law, namely, that what the mind has recently done, 
it tends (within certain limits) to go on doing. 

It is to be noticed, further, that the perception of a 
single object or event is rarely an isolated act of the 
mind. We recognize and understand the things that 

1 Problems of Life and Mind, third series, p. 107. This writer 
employs the word " preperception " to denote, this effect of previous 
perception. 



30 ILLUSIONS OF PERCEPTION. 

surround us through their relations one to another. 
Sometimes the adjacent circumstances and events 
suggest a definite expectation of the new impression. 
Thus, for example, the sound of a gun heard during 
a walk in the country is instantly interpreted by help 
of suggestions due to the previous appearance of the 
sportsman, and the act of raising the gun to his 
shoulder. It may be added that the verbal suggestions 
of others act very much like the suggestions of ex- 
ternal circumstances. If I am told that a gun is going 
to be fired, my mind is prepared for it just as though 
I saw the sportsman. 1 

More frequently the effect of such surrounding 
circumstances is to give an air of familiarity to the new 
impression, to shorten the interval in which the re- 
quired interpretative image is forthcoming. Thus, 
when travelling in Italy, the visual impression answer- 
ing to a ruined temple or a bareheaded friar is con- 
strued much more rapidly than it would be elsewhere, 
because of the attitude of mind due to the surrounding 
circumstances. In all such cases the process of pre- 
perception connected with a given impression is effected 
more or less completely by the suggestions of other 
and related impressions. 

It follows irom all that has been just said that our 
minds are never in exactly the same state of readiness 
with respect to a particular process of perceptional 
interpretation. Sometimes the meaning of an im- 
pression flashes on us at once, and the stage of pre- 

1 Such verbal suggestion, moreover, acting through a sense- 
impression, has something of that vividness of effect which belongs to 
all excitation of mental images by external stimuli 



PHYSIOLOGY OF PERCEPTION. 31 

perception becomes evanescent. At other times the 
same impression will fail for an appreciable interval 
to divulge its meaning. These differences are, no 
doubt, due in part to variations in the state of attention 
at the moment ; but they depend as well on fluctua- 
tions in the degree of the mind's readiness to look at 
the impression in the required way. 

In order to complete this slight analysis of percep- 
tion, we must look for a moment at its physical side, 
that is to say, at the nervous actions which are known 
or supposed with some degree of probability to accom- 
pany it. 

The production of the sensation is known to depend 
on a certain external process, namely, the action of 
some stimulus, as light, on the sense-organ, which 
stimulus has its point of departure in the object, such 
as it is conceived by physical science. The sensation 
arises when the nervous process is transmitted through 
the nerves to the conscious centre, often spoken of as 
the sensorium, the exact seat of which is still a matter 
of some debate. 

The intensification of the sensation by the reaction 
of attention is supposed to depend on some reinforce- 
ment of the nervous excitation in the sensory centre 
proceeding from the motor regions, which are hypo- 
thetically regarded as the centre of attention. 1 The 
classification of the impression, again, is pretty certainly 
correlated with the physical fact that the central ex- 
citation calls into activity elements which have already 
been excited in the same way. 

The nervous counterpart of the final stage of per- 

1 See Wundt, Physiologische Psychologie, p. 723. 



32 ILLUSIONS OF PERCEPTION. 

eeption, the synthesis of the sensation and the 
mental representation, is not clearly ascertained. A 
sensation clearly resembles a mental image in quality. 
It is most obviously marked off from the image by its 
greater vividness or intensity. Agreeably to this view, 
it is now held by a number of eminent physiologists 
and psychologists that the nervous process underlying 
a sensation occupies the same central region as that 
which underlies the corresponding image. According 
to this theory, the two processes differ in their degree 
of energy only, this difference being connected with 
the fact that the former involves, while the latter does 
not involve, the peripheral region of the nervous 
system. Accepting this view as on the whole well 
founded, I shall speak of an ideational, or rather an 
imaginational, and a sensational nervous process, and 
not of an ideational and a sensational centre. 1 

The special force that belongs to the representative 
element in a percept, as compared with that of a pure 
" perceptional " image, 2 is probably connected with the 
fact that, in the case of actual perception, the nervous 
process underlying the act of imaginative construction 
is organically united to the initial sensational process, 
of which indeed it may be regarded as a continuation. 

For the physical counterpart of the two stages in the 

1 For a confirmation of the view adopted in the text, see 
Professor Bain, The Senses and the Intellect, Part II. ch. i. sec. 8 ; 
Herbert Spencer, Principles of Psychology, vol. i. p. 234, et passim; Dr. 
Ferrier, The Functions of the Brain, p. 258, et seq. ; Professor Wundt, 
op. cit., pp. 644, 645 ; G. H. Lewes, Problems of Life and Mind, vol. v. 
p. 445, et seq. For an opposite view, see Dr. Carpenter, Mental 
Physiology, fourth edit., p. 220, etc. ; Dr. Maudsley, The Physiology of 
Mind, ch. v. p. 259, etc. 

2 See note, p. 22. 



SEAT OF SENSATION AND IMAGE. 33 

interpretative part of perception, distinguished as the 
passive stage of preperception, and the active stage of 
perception proper, we may, in the absence of certain 
knowledge, fall back on the hypothesis put forward 
by Dr. J. Hughlings Jackson, in the articles in Brain 
already referred to, namely, that the former answers 
to an action of the right hemisphere of the brain, the 
latter to a subsequent action of the left hemisphere. 
The expediting of the process of preperception in those 
cases where it has frequently been performed before, is 
clearly an illustration of the organic law that every 
function is improved by exercise. And the temporary 
disposition to perform the process due to recent imagi- 
native activity, is explained at once on the physical side 
by the supposition that an actual perception and a per- 
ceptional image involve the activity of the same 
nervous tracts. For, assuming this to be the case, 
it follows, from a well-known organic law, that a 
recent excitation would leave a temporary disposition 
in these particular structures to resume that particular 
mode of activity. 

What has here been said about visual perception 
will apply, mutatis mutandis, to other kinds. Although 
the eye is the organ of perception par excellence, our 
other senses are also avenues by which we intuit and 
recognize objects. Thus touch, especially when it is 
finely developed as it is in the blind, gives an imme- 
diate knowledge of objects — a more immediate know- 
ledge, indeed, of their fundamental properties than 
sight. What makes the eye so vastly superior to the 
organ of touch as an instrument of perception, is first 
of all the range of its action, taking in simultaneously 



34 ILLUSIONS OP PERCEPTION. 

a large number of impressions from objects at a dis- 
tance as well as near ; and secondly, though this may 
seem paradoxical, the fact that it gives us so much 
indirectly, that is, by way of association and sugges- 
tion. This is the interesting side of visual perception, 
that, owing to the vast complex of distinguishable 
sensations of light and colour of various qualities and 
intensities, together with the muscular sensations at- 
tending the varying positions of the organ, the eye is 
able to recognize at any instant a whole external world 
with its fundamental properties and relations. The 
ear comes next to the eye in this respect, but only 
after a long interval, since its sensations (even in the 
case of musical combinations) do not simultaneously 
order themselves in an indefinitely large group of dis- 
tinguishable elements, and since even the comparatively 
few sensations which it is capable of simultaneously 
receiving, being altogether passive — that is to say, 
having no muscular accompaniments — impart but 
little and vague information respecting the external 
order. It is plain, then, that in the study of illusion, 
where the indirectly known elements are the thing to 
be considered, the eye, and after this the ear, will 
mostly engage our attention. 1 

1 Touch gives much by way of interpretation only when an 
individual object, for example a man's hat, is recognized by aid of this 
sense alone, in which case the perception distinctly involves the 
reproduction of a complete visual percept. I may add that the 
organ of smell comes next to that of hearing, with respect both to 
the range and definiteness of its simultaneous sensations, and to the 
amount of information furnished by these. A rough sense of distance 
as well as of direction is clearly obtainable by means of this organ. 
There seems to me no reason why an animal endowed with fine 
olfactory sensibility, and capable of an analytic separation of sense- 



VISUAL AND OTHER PERCEPTION. 35 

So much it seemed needful to say about the 
mechanism of perception, in order to understand the 
slight disturbances of this mechanism that manifest 
themselves in sense-illusion. It may be added that 
our study of these illusions will help still further to 
elucidate the exact nature of perception. Normal 
mental life, as a whole, at once illustrates, and is 
illustrated by, abnormal. And while we need a rough 
provisional theory of accurate perception in order to 
explain illusory perception at all, the investigation of 
this latter cannot fail to verify and even render more 
complete the theory which it thus temporarily adopts. 

Illusions of Perception. 

With this brief psychological analysis of perception 
to help us, let us now pass to the consideration of the 
errors incident to the process, with a view to classify 
them according to their psychological nature and 
origin. 

And here there naturally arises the question, How 
shall we define an illusion of perception? When 
trying to fix the definition of illusion in general, I 
practically disposed of this question. Nevertheless, as 
the point appears to me to be of some importance, I 
shall reproduce and expand one or two of the con- 
siderations then brought forward. 

elements, should not gain a rough perception of an external order 
much more complete than our auditory perception, which is necessarily 
so fragmentary. This supposition appears, indeed, to he the necessary 
complement to the idea first broached, so far as I am aware, by 
Professor Croom Robertson, that to such animals, visual perception 
consists in a reference to a system of muscular feelings defined and 
bounded by strong olfactory sensations, rather than by tactual sen- 
sations as in our case. 



36 ILLUSIONS OF PEECEPTION. 

It is said by certain philosophers that perception, 
as a whole, is an illusion, inasmuch as it involves 
the fiction of a real thing independent of mind, yet 
somehow present to it in the act of sense-perception. 
But this is a question for philosophy, not for science. 
Science, including psychology, assumes that in per- 
ception there is something real, without inquiring 
what it may consist of, or what its meaning may be. 
And though in the foregoing analysis of perception, 
viewed as a complex mental phenomenon or psychical 
process, I have argued that a percept gets its concrete 
filling up out of elements of conscious experience or 
sensations, I have been careful not to contend that the 
particular elements of feeling thus represented are the 
object of perception or the thing perceived. It may 
be that what we mean by a single object with its 
assemblage of qualities is much more than any 
number of such sensations ; and it must be confessed 
that, on the face of it, it seems to be much more. 
And however; this be, the question, What is meant by 
object ; and/is the common persuasion of the existence 
of such an entity in the act of perception accurate or 
illusory ? must be handed over to philosophy. 

"While in the following examination of sense-illu- 
sions we put out of sight what certain philosophers 
say about the illusoriness of perception as a whole, we 
shall also do well to leave out of account what physical 
science is sometimes supposed to tell us respecting a 
constant element of illusion in perception. The phy- 
sicist, by reducing all external changes to "modes of 
motion," appears to leave no room in his world- 
mechanism for the secondary qualities of bodies, such 



ILLUSION OF PERCEPTION DEFINED 37 

as light and heat, as popularly conceived. Yet, while 
allowing this, I think we may still regard the attribu- 
tion of qualities like colour to objects as in the main 
correct and answering to a real fact. When a person 
says an object is red, he is understood by everybody as 
affirming something which is true or false, something 
therefore which either involves an external fact or is 
illusory. It would involve an external fact whenever 
the particular sensation which he receives is the re- 
sult of a physical action (ether vibrations of a certain 
order), which would produce a like sensation in any- 
body else in the same situation and endowed with the 
normal retinal sensibility. On the other hand, an 
illusory attribution of colour would imply that there 
is no corresponding physical agency at work in the 
case, but that the sensation is connected with excep- 
tional individual conditions, as, for example, altered 
retinal sensibility. 

We are now, perhaps, in a position to frame a rough 
definition of an illusion of perception as popularly 
understood. A large number of such phenomena may 
be described as consisting in the formation of percepts 
or quasi-percepts in the minds of individuals under 
external circumstances which would not give rise to 
similar percepts in the case of other people. 

A little consideration, however, will show that this 
is not an adequate definition of what is ordinarily 
understood by an illusion of sense. There are special 
circumstances which are fitted to excite a momentary 
illusion in all minds. The optical illusions due to the 
reflection and refraction of light are not peculiar to 
the individual, but arise in all minds under precisely 
similar external conditions. 



3S ILLUSIONS OF PERCEPTION. 

It is plain that the illusoriness of a perception is 
in these cases determined in relation to the sense- 
impressions of other moments and situations, or to 
what are presumably better percepts than the present 
one. Sometimes this involves an appeal from one 
sense to another. Thus, there is the process of veri- 
fication of sight by touch, for example, in the case 
of optical images, a mode of perception which, as we 
have seen, gives a more direct cognition of external 
quality. Conversely, there may occasionally be a 
reference from touch to sight, when it is a question 
of discriminating two points lying very close to one 
another. Finally, the same sense may correct itself, 
as when the illusion of the stereoscope is corrected by 
afterwards looking at the two separate pictures. 

We may thus roughly define an illusion of percep- 
tion as consisting in the formation of a quasi-percept 
which is peculiar to an individual, or which is con- 
tradicted by another and presumably more accurate 
percept. Or, if we take the meaning of the word 
common to include both the universal as contrasted 
with the individual experience, and the permanent, 
constant, or average, as distinguished from the mo- 
mentary and variable percept, we may still briefly 
describe an illusion of perception as a deviation from 
the common or collective experience. 

Sources of Sense-Illusion. 

Understanding sense-illusion in this way, let us 
glance back at the process of perception in its several 
stages or aspects, with the object of discovering what 
room occurs for illusion. 



HOW SENSE-ILLUSION AEISES. 39 

It appears at first as if the preliminary stages — 
the reception, discrimination, and classification of an 
impression — would not offer the slightest opening for 
error. This part of the mechanism of perception 
seems to work so regularly and so smoothly that one 
can hardly conceive a fault in the process. Never- 
theless, a little consideration will show that even here 
all does not go on with unerring precision. 

Let us suppose that the very first step is wanting — 
distinct attention to an impression. It is easy to see 
that this will favour illusion by leading to a confusion 
of the impression. Thus the timid man will more 
readily fall into the illusion of ghost-seeing than a 
cool-headed observant man, because he is less attentive 
to the actual impression of the moment. This in- 
attention to the sense-impression will be found to 
be a great co-operating factor in the production of 
illusions. 

But if the sensation is properly attended to, can 
there be error through a misapprehension of what is 
actually in the mind at the moment ? To say that 
there can may sound paradoxical, and yet in a sense 
this is demonstrable. I do not mean that there is 
an observant mind behind and distinct from the 
sensation, and failing to observe it accurately through 
a kind of mental short-sightedness. What I mean is 
that the usual psychical effect of the incoming nervous 
process may to some extent be counteracted by a 
powerful reaction of the centres. In the course of our 
study of illusions, we shall learn that it is possible 
for the quality of an impression, as, for example, of 
a sensation of colour, to be appreciably modified 



10 ILLUSIONS OF PERCEPTION. 

when there is a strong tendency to regard it in one 
particular way. 

Postponing the consideration of these, we may say 
that certain illusions appear clearly to take their start 
from an error in the process of classifying or identi- 
fying a present impression. On the physical side, we 
may say that the first stages of the nervous process, 
the due excitation of the sensory centre in accordance 
with the form of the incoming stimulation and the 
central reaction involved in the recognition of the 
sensation, are incomplete. These are so limited and 
comparatively unimportant a class, that it will be 
well to dispose of them at once. 

Confusion of the Sense-Impression. 

The most interesting case of such an error is where 
the impression is unfamiliar and novel in character. 
I have already remarked that in the mental life of 
the adult perfectly new sensations never occur. At 
the same time, comparatively novel impressions some- 
times arise. Parts of the sensitive surface of the body 
which rarely undergo stimulation are sometimes acted 
on, and at other times they receive partially new 
modes of stimulation. In such cases it is plain that 
the process of classing the sensation or recognizing 
it is not completed. It is found that whenever this 
happens there is a tendency to exaggerate the intensity 
of the sensation. The very fact of unfamiliarity seems 
to give to the sensation a certain exciting character. 
As something new and strange, it for the instant 
slightly agitates and discomposes the mind. Being 
unable to classify it with its like, we naturally magnify 



NOVEL SENSE-IMPKESSIONS. 41 

its intensity, and so tend to ascribe it to a dispro- 
portionately large cause. 

For instance, a light bandage worn about the body 
at a part usually free from pressure is liable to be 
conceived as a weighty mass. The odd sense of a 
big cavity in the mouth, which we experience just 
after the loss of a tooth, is probably another illus- 
tration of this principle. And a third example may 
also be supplied from the recollection of the dentist's 
patient, namely, the absurd imagination which he 
tends to form as to what is actually going on in his 
mouth when a tooth is being bored by a modern 
rotating drill. It may be found that the same prin- 
ciple helps to account for the exaggerated importance 
which we attach to the impressions of our dreams. 

It is evident that all indistinct impressions are 
liable to be wrongly classed. Sensations answering to 
a given colour or form, are, when faint, easily confused 
with other sensations, and so an opening occurs for 
illusion. Thus, the impressions received from distant 
objects are frequently misinterpreted, and, as we shall 
see by-and-by, it is in this region of hazy impression 
that imagination is wont to play its most startling 
pranks. 

It is to be observed that the illusions arising from 
wrong classification will be more frequent in the case 
of those senses where discrimination is low. Thus, it 
is much easier in a general way to confuse two 
sensations of smell than two sensations of colour. 
Hence the great source of such errors is to be found 
in that mass of obscure sensation which is connected 
with the organic processes, as digestion, respiration, etc., 



42 ILLUSIONS OP PERCEPTION. 

together with those varying tactual and motor feelings 
which result from what is called the subjective stimu- 
lation of the tactual nerves, and from changes in the 
position and condition of the muscles. Lying com- 
monly in what is known as the sub-conscious region 
of mind, undiscriminated, vague, and ill-defined, these 
sensations, when they come to be specially attended to, 
readily get misapprehended, and so lead to illusion, 
both in waking life and in sleep. I shall have 
occasion to illustrate this later on. 

With these sensations, the result of stimulations 
coming from remote parts of the organism, may be 
classed the ocular impressions which we receive in 
indirect vision. When the eye is not fixed on an 
object, the impression, involving the activity of some 
peripheral region of the retina, is comparatively indis- 
tinct. This will be much more the case when the object 
lies at a distance for which the eye is not at the time 
accommodated. And in these circumstances, when we 
happen to turn our attention to the impression, we 
easily misapprehend it, and so fall into illusion. Thus, 
it has been remarked by Sir David Brewster, in his 
Letters on Natural Magic (letter vii.), that when looking 
through a window at some object beyond, we easily 
suppose a fly on the window-pane to be a larger object, 
as a bird, at a greater distance. 1 

1 It may be said, perhaps, that the exceptional direction of attention, 
by giving an unusual intensity to the impression, causes us to exagge- 
rate it just as in the case of a novel sensation. An effort of attention 
directed to any of our vague bodily sensations easily leads us to 
magnify its cause. A similar confusion may arise even in direct 
vision, when the objects are looked at in a dim light, through a want 
of proper accommodation. (See Sir D. Brewster, op. cit., letter i.) 



INDISTINCT SENSE-IMIEESSIONS. 43 

"While these cases of a confusion or a wrong classi- 
fication of the sensation are pretty well made out, there 
are other illusions or quasi-illusions respecting which 
it is doubtful whether they should be brought under 
this head. For example, it was found by Weber, 
that when the legs of a pair of compasses are at a 
certain small distance apart they will be felt as two 
by some parts of the tactual surface of the body, but 
only as one by other parts. How are we to regard 
this discrepancy ? Must we say that in the latter case 
there are two sensations, only that, being so similar, 
they are confused one with another ? There seems 
some reason for so doing, in the fact that, by a re- 
peated exercise of attention to the experiment, they 
may afterwards be recognized as two. 

We here come on the puzzling question, How much 
in the character of the sensation must be regarded 
as the necessary result of the particular mode of nervous 
stimulation at the moment, together with the laws of 
sensibility, and how much must be put down to the 
reaction of the mind in the shape of attention and 
discrimination ? For our present purpose we may say 
that, whenever a deliberate effort of attention does 
not suffice to alter the character of a sensation, this 
may be pretty safely regarded as a net result of the 
nervous process, and any error arising may be referred 
to the later stages of the process of perception. Thus, 
for example, the taking of the two points of a pair of 
compasses for one, where the closest attention does not 
discover the error, is best regarded as arising, not from 
a confusion of the sense-impression, but from a wrong 
interpretation of a sensation, occasioned by an over- 



44 ILLUSIONS OF PERCEPTION. 

lookin* 
bility. 



looking of the limits of local discriminative sensi- 



Misinterpretation of the Sense-Impression. 

Enough, has been said, perhaps, about those errors 
of.perception which have their root in the initial pro- 
cess of sensation. We may now pass to the far more 
important class of illusions which are related to the later 
stages of perception, that is to say, the process of inter- 
preting the sense-impression. Speaking generally, one 
may describe an illusion of perception as a misinter- 
pretation. The wrong kind of interpretative mental 
image gets combined with the impression, or, if with 
Helmholtz we regard perception as a process of "un- 
conscious inference," we may say that these illusions 
involve an unconscious fallacious conclusion. Or, 
looking at the physical side of the operation, it may 
be said that the central course taken by the nervous 
process does not correspond to the external relations 
of the moment. 

As soon as we inspect these illusions of inter- 
pretation, we see that they fall into two divisions, 
according as they are connected with the process of 
suggestion, that is to say, the formation of the inter- 
pretative image so far as determined by links of 
association with the actual impression, or with an in- 
dependent process of preperception as explained above. 
Thus, for example, we fall into the illusion of hearing 
two voices when our shout is echoed back, just because 
the second auditory impression irresistibly calls up 
the image of a second shouter. On the other hand, a 
man experiences the illusion of seeing spectres of 



PASSIVE AND ACTIVE ILLUSIONS. 45 

familiar objects just after exciting his imagination 
over a ghost-story, because the mind is strongly pre- 
disposed to frame this kind of percept. The first 
class of illusions arises from without, the sense-im- 
pression being the starting-point, and the process of 
preperception being controlled by this. The second 
class arises rather from within, from an independent or 
spontaneous activity of the imagination. In the one 
case the mind is comparatively passive ; in the other 
it is active, energetically reacting on the impression, 
and impatiently anticipating the result of the normal 
process of preperception. Hence I shall, for brevity's 
sake, commonly speak of them as Passive and Active 
Illusions. 1 

I may, perhaps, illustrate these two classes of illusion 
by the simile of an interpreter poring over an old 
manuscript. The first would be due to some 
peculiarity in the document misleading his judgment, 
the second to some caprice or preconceived notion in 
the interpreter's mind. 

It is not difficult to define conjecturally the 
physiological conditions of these two large classes of 
illusion. On the physical side, an illusion of sense, 
like a just perception, is the result of a fusion of the 
nervous process answering to a sensation with a 
nervous process answering to a mental image. In 
the case of passive illusions, this fusion may be said 
to take place in consequence of some point of con- 
nection between the two. The existence of such a 
connection appears to be involved in the very fact of 

1 They might also be distinguished as objective and subjective 
illusions, or as illusions a posteriori and illusions a priori. 



46 ILLUSIONS OF PERCEPTION. 

suggestion, and may be said to be the organic result 
of frequent conjunctions of the two parts of the nervous 
operation in our past history. In the case of active 
illusions, however, which spring rather from the in- 
dependent energy of a particular mode of the 
imagination, this point of organic connection is not 
the only or even the main thing. In many cases, as 
we shall see, there is only a faint shade of resem- 
blance between the present impression and the mental 
image with which it is overlaid. The illusions de- 
pendent on vivid expectation thus answer much less 
to an objective conjunction of past experiences than to 
a capricious subjective conjunction of mental images. 
Here, then, the fusion of nervous processes must have 
another cause. And it is not difficult to assign such a 
cause. The antecedent activity of imagination doubt- 
less involves as its organic result a powerful temporary 
disposition in the nervous structures concerned to go on 
acting. In other words, they remain in a state of sub- 
excitation, which can be raised to full excitation by a 
slight additional force. The more powerful this dis- 
position in the centres involved in the act of imagina- 
tion, the less the additional force of external stimulus 
required to excite them to full activity. 

Considering the first division, passive illusions, a 
little further, we shall see that they may be broken 
up into two sub-classes, according to the causes of the 
errors. In a general way we assume that the impression 
always answers to some quality of the object which 
is perceived, and varies with this ; that, for example, our 
sensation of colour invariably represents the quality 
of external colour which we attribute to the object. 



CONDITIONS OF PASSIVE ILLUSION. 47 

Or, to express it physically, we assume that the ex- 
ternal force acting on the sense-organ invariably 
produces the same effect, and that the effect always 
varies with the external cause. But this assumption, 
though true in the main, is not perfectly correct. It 
supposes that the organic conditions are constant, and 
that the organic process faithfully reflects the external 
operation. Neither of these suppositions is strictly 
true. Although in general we may abstract from the 
organism and view the relation between the external 
fact and the mental impression as direct, we cannot 
always do so. 

This being so, it is possible for errors of perception 
to arise through peculiarities of the nervous organi- 
zation itself. Thus, as I have just observed, sensibility 
has its limits, and these limits are the starting-point 
in a certain class of widely shared or common illusions. 
An example of this variety is the taking of the two 
points of a pair of compasses for one by the hand, 
already referred to. Again, the condition of the ner- 
vous structures varies indefinitely, so that one and the 
same stimulus may, in the case of two individuals, or 
of the same individual at different times, produce 
widely unlike modes of sensation. Such variations 
are clearly fitted to lead to gross individual errors as 
to the external cause of the sensation. Of this sort 
is the illusory sense of temperature which we often 
experience through a special state of the organ em- 
ployed. 

While there are these errors of interpretation due 
to some peculiarity of the organization, there are 
others which involve no such peculiarity, but arise 



4:8 ILLUSIONS OF PERCEPTION. 

through the special character or exceptional confor- 
mation of the environment at the moment. Of this 
order are the illusions connected with the reflection of 
light and sound. We may, perhaps, distinguish the 
first sub-class as organically conditioned illusion's, and 
the second as extra-organically determined illusions. 
It may be added that the latter are roughly describable 
as common illusions. They thus answer in a measure 
to the first variety of organically conditioned illusions, 
namely, those connected with the limits of sensibility. 
On the other hand, the active illusions, being es- 
sentially individual or subjective, may be said to 
correspond to the other variety of this class — those 
connected with variations of sensibility. 

Our scheme of sense-illusions is now complete. 
First of all, we shall take up the passive illusions, 
beginning with those which are conditioned by special 
circumstances in the organism. After that we shall 
illustrate those which depend on peculiar circumstances 
in the environment. And finally, we shall separately 
consider what I have called the active illusions of 
sense. 

It is to be observed that these illusions of per- 
ception properly so called, namely, the errors arising 
from a wrong interpretation of an impression, and, 
not from a confusion of one impression with another 
are chiefly illustrated in the region of the two higher 
senses, sight and hearing. For it is here, as we 
have seen, that the interpretative imagination has 
most work to do in evolving complete percepts of 
material, tangible objects, having certain relations in 
space, out of a limited and homogeneous class of 



SCHEME OF SENSE ILLUSIONS. 49 

sensations, namely, those of light and colour, and of 
sound. As I have before observed, tactual perception, 
in so far as it is the recognition of an object of a certain 
size, hardness, and distance from our body, involves the 
least degree of interpretation, and so offers little room 
for error ; it is only when tactual perception amounts to 
the recognition of an individual object, clothed with 
secondary as well as primary qualities, that an opening 
for palpable error occurs. 

With respect, however, to the first sub-class of 
these illusions, namely, those arising from organic 
peculiarities which give a twist, so to speak, to the 
sensation, no very marked contrast between the 
different senses presents itself. So that in illustrating 
this group we shall be pretty equally concerned with 
the various modes of perception connected with the 
different senses. 

It may be said once for all that in thus marking 
off from one another certain groups of illusion, I am 
not unmindful of the fact that these divisions answer 
to no very sharp natural distinctions. In fact, it will 
be found that one class gradually passes into the other, 
and that the different characteristics here separated 
often combine in a most perplexing way. All that is 
claimed for this classification is that it is a convenient 
mode of mapping out the subject. 



CHAPTER IV. 

ILLUSIONS OF peeception — continued. 

A. Passive Illusions (a) as determined by the Organism. 

In" dealing with the illusions which are related to 
certain peculiarities in the nervous organism and the 
laws of sensibility, I shall commence with those which 
are connected with certain limits of sensibility. 

Limits of Sensibility. 

To begin with, it is known that the sensation does 
not always answer to the external stimulus in its degree 
or intensity. Thus, a certain amount of stimulation 
is necessary before any sensation arises. And this will, 
of course, be greater when there is little or no attention 
directed to the impression, that is to say, no co-opera- 
ting central reaction. Thus it happens that slight 
stimuli go overlooked, and here illusion may have its 
starting-point. The most familiar example of such 
slight errors is that of movement. When we are look- 
ing at objects, our ocular muscles are apt to execute 
very slight movements which escape our notice. Hence 
we tend, under certain circumstances, to carry over the 
retinal result of the movement, that is to say, the im- 



EELATION OF STIMULUS TO SENSATION. 51 

pression produced by a shifting of the parts of the retinal 
image to new nervous elements, to the object itself, 
and so to transform a "subjective" into an "objective" 
movement. In a very interesting work on apparent or 
illusory movements, Professor Hoppe has fully investi- 
gated the facts of such slight movements, and endea- 
voured to specify their causes. 1 

Again, even when the stimulus is sufficient to pro- 
duce a conscious impression, the degree of the feeling 
may not represent the degree of the stimulus. To 
take a very inconspicuous case, it is found by Fechner 
that a given increase of force in the stimulus produces 
a less amount of difference in the resulting sensations 
when the original stimulus is a powerful one than 
when it is a feeble one. It follows from this, that 
differences in the degree of our sensations do not 
exactly correspond to objective differences. For 
example, we tend to magnify the differences of light 
among objects, all of which are feebly illuminated, that 
is to say, to see them much more removed from one 
another in point of brightness than when they are 
more strongly illuminated. Helmholtz relates that, 
owing to this tendency, he has occasionally caught 
himself, on a dark night, entertaining the illusion that 

1 Die Schein-Beioegungen, von Professor Dr. J. I. Hoppe (1879) ; 
cf. an ingenious article on " Optical Illusions of Motion," by Professor 
Silvanus P. Thompson, in Brain, October, 1880. These illusions fre- 
quently involve the co-operation of some preconception or expectation. 
For example, the apparent movement of a train when we are watching 
it and expecting it to move, involves both an element of sense- 
impression and of imagination. It is possible that the illusion of 
table-turning rests on the same basis, the table-turner being unaware 
of the fact of exerting a certain amount of muscular force, and vividly 
expecting a movement of the object. 



52 ILLUSIONS OF PEECEPTION. 

the comparatively bright objects visible in twilight 
were self-luminous. 1 

Again, there are limits to the conscious separation 
of sensations which are received together, and this fact 
gives rise to illusion. In general, the number of 
distinguishable sensations answers to the number of 
external causes ; but this is not always the case, and 
here we naturally fall into the error of mistaking the 
number of the stimuli. Reference has already been 
made to this fact in connection with the question 
whether consciousness can be mistaken as to the 
character of a present feeling. 

The case of confusing two impressions when the 
sensory fibres involved are very near one another, has 
already been alluded to. Both in touch and in sight 
we always take two or more points for one when they 
are only separated by an interval that falls below the 
limits of local discrimination. It seems to follow 
from this that our perception of the world as a con- 
tinuum, made up of points perfectly continuous one 
with another may, for what we know, be illusory. 
Supposing the universe to consist of atoms separated 
by very fine intervals, then it is demonstrable that it 
would appear to our sensibility as a continuum, just as 
it does now. 2 

Two or more simultaneous sensations are indis- 

1 Physiologfcche Ojptilc, p. 316. 

2 It is plain that this supposed error could only be brought under 
our definition of illusion by extending the latter, so as to include 
sense-perceptions which are contradicted by reason employing idealized 
elements of sense -impression, which, as Lewes has shown (Problems of 
Life and Mind, i. p. 2 GO), make up the "extra-sensible world "of 
science. 



COALESCENCE OF SENSATIONS. 53 

tinguishable from one another, not only when they 
have nearly the same local origin, but under other 
circumstances. The blending of partial sensations of 
tone in a Z;Zcmf7-sensation, and the coalescence in certain 
cases of the impressions received by way of the two 
retinas, are examples of this. It is not quite cer- 
tain what determines this fusion of two simultaneous 
feelings. It may be said generally that it is favoured 
by similarity between the sensations -, 1 by a compara- 
tive feebleness of one of the feelings ; by the fact of 
habitual concomitance, the two sensations occurring 
rarely, if ever, in isolation ; and by the presence of a 
mental disposition to view them as answering to one 
external object. These considerations help us to ex- 
plain the coalescence of the retinal impressions and its 
limits, the fusion of partial tones, and so on. 2 

It is plain that this fusion of sensations, whatever 
its exact conditions may be, gives rise to error or 
wrong interpretation of the sense-impression. Thus, to 
take the points of two legs of a pair of compasses for 
one point is clearly an illusion of perception. Here 
is another and less familiar example. Very cold and 
smooth surfaces^ as those of metal, often appear to be 
wet. I never feel sure, after wiping the blades of my 
skates, that they are perfectly dry, since they always 

1 An ingenious writer, M. Binet, has tried to prove that the fusion 
of homogeneous sensations, having little difference of local colour, is 
an illustration of this principle. (See the Revue Fhilosophique, 
September, 1SS0.) 

2 Even the fusion of elementary sensations of colour, on the 
hypothesis of Young and Helmholtz, in a seemingly simple sensation 
may be explained to some extent by these circumstances, more espe- 
cially the identity of local interpretation. 



54 ILLUSIONS OF PEKCEPTION. 

seem more or less damp to my hand. What is the 
reason of this ? Helmholtz explains the phenomenon 
by saying that the feeling we call by the name 01 
wetness is a compound sensation consisting of one of 
temperature and one of touch proper. These sen- 
sations occurring together so frequently, blend into 
one, and so we infer, according to the general instinc- 
tive tendency already noticed, that there is one 
specific quality answering to the feeling. And since 
the feeling is nearly always produced by surfaces 
moistened by cold liquid, we refer it to this circum- 
stance, and speak of it as a feeling of wetness. Hence, 
when the particular conjunction of sensations arises 
apart from this external circumstance, we erroneously 
infer its presence. 1 

The most interesting case of illusion connected 
with the fusion of simultaneous sensations is that of 
single vision, or the deeply organized habit of com- 
bining the sensations of what are called the corre- 
sponding points of the two retinas. This coalescence 
of two sensations is so far erroneous since it makes us 
overlook the existence of two distinct external agencies 
acting on different parts of the sensitive surface of the 
body. And this is the more striking in the case of 

1 The perception of lustre as a single quality seems to illustrate 
a like error. There is good reason to suppose that this impression 
arises through a difference of brightness in the two retinal images 
due to the regularly reflected light. And so when this inequality 
of retinal impression is imitated, as it may easily be by combining a 
black and a white surface in a stereoscope, we imagine that we are 
looking at one lustrous surface. (See Helmholtz, Physiologische 
Optik, p. 782, etc., and Popular e wissenschaftliche Vortrage, 2tes Heft, 
p. 80.) 



AFTEK-SENSATION. 55 

looking at solid objects, since here it is demonstrable 
that the forces acting on the two retinas are not 
perfectly similar. Nevertheless, such a coalescence 
plainly answers to the fact that these external agencies 
usually arise in one and the same object, and this unity 
of the object is, of course, the all-important thing to 
be sure of. 

This habit may, however, beget palpable illusion 
in another way. In certain exceptional cases the 
coalescence does not take place, as when I look at a 
distant object and hold a pencil just before my eyes. 1 
And in this case the organized tendency to take one 
visual impression for one object asserts its force, and I 
tend to fall into the illusion of seeing two separate 
pencils. If I do not wholly lapse into the error, it is 
because my experience has made me vaguely aware 
that double images under these circumstances answer 
to one object, and that if there were really two pencils 
present I should have four visual impressions. 

Once more, it is a law of sensory stimulation that 
an impression persists for an appreciable time after 
the cessation of the action of the stimulus. This 
" after sensation " will clearly lead to illusion, in so far 
as we tend to think of the stimulus as still at work. 
It forms, indeed, as will be seen by-and-by, the 
simplest and lowest stage of hallucination. Some- 
times this becomes the first stage of a palpable error. 
After listening to a child crying for some time the ear 

1 The conditions of the production of these double images have 
been accurately determined by Helmholtz, -who shows that the 
coalescence of impressions takes place whenever the object is so 
situated in the field of vision as to make it practically necessary that 
it should be recognized as one. 



5(3 ILLUSIONS OF PERCEPTION. 

easily deceives itself into supposing that the noise is 
continued when it has actually ceased. Again, after 
taking a bandage from a finger, the tingling and 
other sensations due to the pressure sometimes per- 
sist for a good time, in which case they easily give 
rise to an illusion that the finger is still bound. 

It follows from this fact of the reverberation of the 
nervous structures after the removal of a stimulus, that 
whenever two discontinuous stimulations follow one 
another rapidly enough, they will appear continuous. 
This fact is a fruitful source of optical illusion. The 
appearance of a blending of the stripes of colours 
on a rotating disc or top, of the formation of a ring of 
light by swinging round a piece of burning wood, and 
the illusion of the toy known as the thaumatrope, or 
wheel of life, all depend on this persistence of retinal 
impression. Many of the startling effects of sleight of 
hand are undoubtedly due in part to this principle. 
If two successive actions or sets of circumstances to 
which the attention of the spectator is specially directed 
follow one another by a very narrow interval of time, 
they easily appear continuous, so that there seems 
absolutely no time for the introduction of an inter- 
mediate step. 1 

There is another limit to sensibility which is in a 
manner the opposite to the one just named. It is a 

1 These illusions are, of course, due in part to inattention, since 
close critical scrutiny is often sufficient to dispel them. They are 
also largely promoted by a preconception that the event is going to 
happen in a particular way. But of this more further on. I may add 
that the late Professor Clifford has argued ingeniously against the 
idea of the world being a continuum, by extending this idea of the 
wheel of life. (See Lectures and Essays, i. p. 112, et seq.) 



PEOLONGED STIMULATION. 57 

law of nervous stimulation that a continued activity of 
any structure results in less and less psychic result, 
and that when a stimulus is always at work it ceases 
in time to have any appreciable effect. The common 
illustration of this law is drawn from the region of 
sound. A constant noise, as of a mill, ceases to pro- 
duce any conscious sensation. This fact, it is plain, 
may easily become the commencement of an illusion. 
Not only may we mistake a measure of noise for perfect 
silence, 1 we may misconceive the real nature of ex- 
ternal circumstances by overlooking some continuous 
impression. 

Curious illustrations of this effect are found in 
optical illusions, namely, the errors we make re- 
specting the movement of stationary objects after 
continued movement of the eyes. When, for example, 
in a railway carriage we have for some time been 
following the (apparent) movement of objects, as trees, 
etc., and turn our eyes to an apparently stationary 
object, as the carpet of the compartment, this seems to 
move in the contrary direction to that of the trees. 
Helmholtz's explanation of this illusion is that when 
we suppose that we are fixing our eye on the carpet we 
are really continuing to move it over the surface by 
reason of the organic tendency, already spoken of, to go 
on doing anything that has been done. But since we 
are unaware of this prolonged series of ocular move- 
ments, the muscular feelings having become faint, we 
take the impression produced by the sliding of the 

1 It is supposed that in the case of every sense-organ there is 
always some minimum forces of stimulus at work, the effect of which 
on our consciousness is nil. 



58 ILLUSIONS OF PERCEPTION. 

picture over the retina to be the result of a movement 
of the object. 1 

Another limit to our sensibility, which needs to be 
just touched on here, is known by the name of the 
specific energy of the nerves. One and the same nerver 
fibre always reacts in a precisely similar way, whatever 
the nature of the stimulus. Thus, when the optic nerve 
is stimulated in any manner, whether by light, me- 
chanical pressure, or an electric current, the same 
effect, a sensation of light, follows. 2 In a usual way, a 
given class of nerve-fibre is only stimulated by one 
kind of stimulus. Thus, the retina, in ordinary circum- 
stances, is stimulated by light. Owing to this fact, 
there has arisen a deeply organized habit of translating 
the impression in one particular way. Thus, I in- 
stinctively regard a sensation received by means of 
the optic nerve as one caused by light. 

Accordingly, whenever circumstances arise in which 
a like sensation is produced by another kind of stimu- 
lus, we fall into illusion. The phosphenes, or circles of 
light which are seen when the hinder part of the eye- 

1 See Helmholtz, Physiologische Optih, p. 603. Helinkoltz's ex- 
planation is criticised by Dr. Hoppe, in the work already referred to 
(sec. vii.), though I cannot see that his own theory of these move- 
ments is essentially different. The apparent movement of objects in 
vertigo, or giddiness, is probably due to the loss, through a physical 
cause, of the impressions made by the pressure of the fluid contents of 
the ear on the auditory fibres, by which the sense of equilibrium and 
of rotation is usually received. (See Ferrier, Functions of the Brain, 
pp. 60, 61.) 

2 I do not need here to go into the question whether, as Johannes 
Miiller assumed, this is an original attribute of nerve-structure, or 
whether, as Wundt suggests, it is due simply to the fact that certain 
kinds of nervous fibre have, in the course of evolution, been slowly 
adapted to one kind of stimulus. 



SPECIFIC ENERGY OF NERVES. 59 

ball is pressed, may be said to be illusory in so far as 
we speak of thern as perceptions of light, thus referring 
them to the external physical agency which usually 
causes them. The same remark applies to those 
" subjective sensations," as they are called, which are 
known to have as their physical cause subjective 
stimuli, consisting, in the case of sight, in varying 
conditions of the peripheral organ, as increased blood- 
pressure. Strictly speaking, such simple feelings as 
these appear to be, involve an ingredient of false per- 
ception : in saying that we perceive light at all, we go 
beyond the pure sensation, interpreting this wrongly. 

Very closely connected with this limitation of our 
sensibility is another which refers to the consciousness 
of the local seat, or origin of the impression. This 
has so far its basis in the sensation itself as it is well 
known that (within the limits of local discrimination, 
referred to above) sensations have a particular "local" 
colour, which varies in the case of each of the nervous 
fibres by the stimulation of which they arise. 1 But 
though this much is known through a difference in 
the sensibility, nothing more is known. Nothing can 
certainly be ascertained by a mere inspection of the 
sensation as to the distance the nervous process has 
travelled, whether from the peripheral termination of 
the fibre or from some intermediate point. 

In a general way, we refer our sensations to the 
peripheral endings of the nerves concerned, according 
to what physiologists have called " the law of eccen- 

1 I here refer to what is commonly supposed to he the vague 
innate difference of sensation according to the local origin, before this 
is rendered precise, and added to by experience and association. 



60 ILLUSIONS OF PERCEPTION. 

tricity." Thus I am said to feel the pain caused by 
a bruise in the foot in the member itself. This applies 
also to some of the sensations of the special senses. 
Thus, impressions of taste are clearly localized in the 
corresponding peripheral terminations. 

With, respect to the sense of smell, and still more 
to those of hearing and sight, where the impression is 
usually caused by an object at a distance from the 
peripheral organ, our attention to this external cause 
leads us to overlook in part the "bodily seat" of the 
sensation. Yet even here we are dimly aware that 
the sensation is received by way of a particular part of 
the sensitive surface, that is to say, by a particular 
sense-organ. Thus, though referring an odour to a dis- 
tant flower, we perceive that the sensation of odour has 
its bodily origin in the nose. And even in the case of 
hearing and sight, we vaguely refer the impressions, as 
such, to the appropriate sense-organ. There is, indeed, 
in these cases a double local reference, a faint one to 
the peripheral organ which is acted on, and a more dis- 
tinct one to the object or the force in the environment 
which acts on this. 

Now, it may be said that the act of localization is 
in itself distinctly illusory, since it is known that the 
sensation first arises in connection with the excitation 
of the sensory centre, and not of the peripheral fibre. 1 

1 The illusory character of this simple mode of perception is seen 
best, perhaps, in the curious habit into which we falL of referring 
a sensation of contact or discomfort to the edge of the teeth, the hair, 
and the other insentient structures, and even to anything customarily 
attached to the sentient surface, as dress, a pen, graving tool, etc. 
On these curious illusions, see Lotze, Mihroko&mus, third edit., vol. ii* 
p 202, etc. ; Taine, De I 'Intelligence, torn. ii. p. 83, et seq. 



LOCALIZATION OF IMPRESSION. 61 

Yet it must at least be allowed that this localization of 
sensation answers to the important fact that, under 
usual circumstances, the agency producing the sensa- 
tion is applied at this particular point of the organism, 
the knowledge of which point is supposed by modern 
psychologists to have been very slowly learnt by the 
individual and the race, through countless experiments 
with the moving organ of touch, assisted by the eye. 

Similarly, the reference of the impression, in the 
case of hearing and sight, to an object in the environ- 
ment, though, as we have seen, from one point of view 
illusory, clearly answers to a fact of our habitual ex- 
perience ; for in an immense preponderance of cases at 
least a visual or auditory impression does arise through 
the action on the sense-organ of a force (ether or air 
waves) proceeding from a distant object. 

In some circumstances, however, even this element 
of practical truth disappears, and the localization of 
the impression, both within and without the organism, 
becomes altogether illusory. This result is involved in 
the illusions, already spoken of, which arise from the 
instinctive tendency to refer sensations to the ordinary 
kind of stimulus. Thus, when a feeling resulting 
from a disturbance in the optic nerve is interpreted 
as one of external light vaguely felt to be acting on 
the eye, or one resulting from some action set up 
in the auditory fibre as a sensation of external sound 
vaguely felt to be entering the ear, we see that the 
error of localization is a consequence of the other error 
already characterized. 

As I have already observed, an excitation of a 
nerve at any other point than the peripheral termi- 



62 ILLUSIONS OF PERCEPTION. 

nation, occurs but rarely in normal life. One familiar 
instance is the stimulation of the nerve running to 
the hand and fingers, by a sharp blow on the elbow 
over which it passes. As everybody knows, this gives 
rise to a sense of pain at the extremities of the nerve. 
The most common illustration of such errors of locali- 
zation is found in subjective sensations, such as the 
impression we sometimes have of something creeping 
over the skin, of a disagreeable taste in the mouth, 
of luminous spots floating across the field of vision, 
and so on. The exact physiological seat of these is 
often a matter of conjecture only ; yet it may safely 
be said that in many instances the nervous excitation 
originates at some point considerably short of its peri- 
pheral extremity : in which case there occurs the 
illusion of referring the impressions to the peripheral 
sense-organ, and to an external force acting on this. 

The most striking instances of these errors of 
localization are found in abnormal circumstances. 
It is well known that a man who has lost a leg 
refers all sensations arising from a stimulation of the 
truncated fibres to his lost foot, and in some cases has 
even to convince himself of the non-existence of his 
lost member by sight or touch. Patients often de- 
scribe these experiences in very odd language. " If," 
says one of Dr. Weir Mitchell's patients, " I should 
say I am more sure of the leg which ain't than the 
one which air, I guess I should be about correct." 1 

1 Quoted by G. H. Lewes, Problems of Life and Mind, third 
series, p. 335. These illusions are supposed to involve an excitation 
of the nerve-fibres (whether sensory or motor) which run to the 
muscles and yh-ld the so-called muscular sensations. 



ILLUSOEY LOCALIZATION". 63 

There is good reason for supposing that this source 
of error plays a prominent part in the illusions of the 
insane. Diseased centres may be accompanied by 
disordered peripheral structures, and so subjective 
sensation may frequently be the starting-point of the 
wildest illusions. Thus, a patient's horror of poison 
may have its first origin in some subjective gustatory 
sensation. Similarly, subjective tactual sensations may 
give rise to gross illusions, as when a patient " feels " 
his body attacked by foul and destructive creatures. 

It may be well to remark that this mistaken in- 
terpretation of the seat or origin of subjective sensation 
is closely related to hallucination. In so far as the 
error involves the ascription of the sensation to a 
force external to the sense-organ, this part of the 
mental process must, when there is no such force 
present, be viewed as hallucinatory. Thus, the feeling 
of something creeping over the skin is an hallucination 
in the sense that it implies the idea of an object ex- 
ternal to the skin. Similarly, the projection of an 
ocular impression due to retinal disturbance into the 
external field of vision, may rightly be named an hallu- 
cination. But the case is not always so clear as this. 
Thus, for example, when a gustatory sensation is the 
result of an altered condition of the saliva, it may be 
said that the error is as much an illusion as an hallu- 
cination. 1 

In a wide sense, again, all errors connected with 

1 It is brought out by Griesinger (Joe. cit.) and the other writera 
on the pathology of illusion already quoted, that in the case of 
subjective sensations of touch, taste, and smell, no sharp line can be 
drawn between illusion and hallucination. 



64 ILLUSIONS OF PERCEPTION. 

those subjective sensations which arise from a stimu- 
lation of the peripheral regions of the nerve may be 
called illusions rather than hallucinations. Or, if they 
must be called hallucinations, they may be dis- 
tinguished as " peripheral " from those " central " 
hallucinations which arise through an internal auto- 
matic excitation of the sensory centre. It is plain 
from this that the region of subjective sensation is an 
ambiguous region, where illusion and hallucination mix 
and become confused. To this point I shall have 
occasion to return by-and-by. 

I have now probably said enough respecting the 
illusions that arise through the fact of there being 
fixed limits to our sensibility. The rationale of these 
illusions is that whenever the limit is reached, we tend 
to ignore it and to interpret the impression in the 
customary way. 

Variations of Sensibility. 

We will now pass to a number of illusions which 
depend on something variable in the condition of our 
sensibility, or some more or less exceptional organic 
circumstance. These variations may be momentary 
and transient or comparatively permanent. The illu- 
sion arises in each case from our ignoring the variation, 
and treating a given sensation under all circumstances 
as answering to one objective cause. 

First of all, the variation of organic state may 
affect our mental representation of the strength of the 
stimulus or external cause. Here the fluctuation may 
be a temporary or a permanent one. The first case is 
illustrated in the familiar example of taking a room 



HYPERESTHESIA AND ANESTHESIA. 65 

to be brighter than it is when emerging from a dark 
one. Another striking example is that of our sense 
of the temperature of objects, which is known to be 
strictly relative to a previous sensation, or more cor- 
rectly to the momentary condition of the organ. Yet, 
though every intelligent person knows this, the deeply 
rooted habit of making sensation the measure of 
objective quality asserts its sway, and frequently leads 
us into illusion. The well-known experiment of first 
plunging one hand in cold water, the other in hot, and 
then dipping them both in tepid, is a startling example 
of this organized tendency. For here we are strongly 
disposed to accept the palpable contradiction that the 
same water is at once warm and cool. 

Far more important than these temporary fluctu- 
ations of sensibility are the permanent alterations. 
Excessive fatigue, want of proper nutrition, and certain 
poisons are well known to be causes of such changes. 
They appear most commonly under two forms, exalted 
sensibility, or hyperesthesia, and depressed sensibility, 
or aneesthesia. In these conditions flagrant errors are 
made as to the real magnitude of the causes of the 
sensations. These variations may occur in normal life 
to some extent. In fairly good health we experience at 
times strange exaltations of tactual sensibility, so that 
a very slight stimulus, such as the contact of the bed- 
clothes, becomes greatly exaggerated. 

In diseased states of the nervous system these 
variations of sensibility become much more striking. 
The patient who has hyperesthesia fears to touch a 
perfectly smooth surface, or he takes a knock at the 
door to be a clap of thunder. The hypochondriac may, 



66 ILLUSIONS OF PEECEPTION. 

through an increase of organic sensibility, translate 
organic sensations as the effect of some living creature 
gnawing at his vitals. Again, states of anaesthesia 
lead to odd illusions among the insane. The common 
supposition that the body is dead, or made of wood 
or of glass, is clearly referable in part to lowered sensi- 
bility of the organism. 1 

It is worth adding, perhaps, that these variations 
in sensibility give rise not only to sensory but also to 
motor illusions. To take a homely instance, the last 
miles of a long walk seem much longer than the first, 
not only because the sense of fatigue leading us to 
dwell on the transition of time tends to magnify the 
apparent duration, but because the fatigued muscles and 
connected nerves yield a new set of sensations which 
constitute an exaggerated standard of measurement. 
A number of optical illusions illustrate the same 
thing. Our visual sense of direction is determined in 
part by the feelings accompanying the action of the 
ocular muscles, and so is closely connected with the 
perception of movement, which, has already been 
touched on. If an ocular muscle is partially para- 
lyzed it takes a much greater " effort " to effect a given 
extent of movement than when the muscle is sound. 
Hence any movement performed by the eye seems 
exaggerated. Hence, too, in this condition objects are 
seen in a wrong direction ; for the patient reasons 
that they are where they would seem to be if he had 
executed a wider movement than he really has. This 
may easily be proved by asking him to try to seize 

1 For a fuller account of these pathological disturbances of 
sensibility, see Griesinger; also Dr. A. Mayer, Die Sinnestauschungen. 



PARESTHESIA. 67 

the object with his hand. The effect is exaggerated 
when complete paralysis sets in, and no actual move- 
ment occurs in obedience to the impulse from 
within. 1 

Variations in the condition of the nerve affect not 
only the degree, but also the quality of the sensation, 
and this fact gives rise to a new kind of illusion. 
The curious phenomena of colour-contrast illustrate 
momentary alterations of sensibility. When, after 
looking at a green colour for a time, I turn my eye 
to a grey surface and see this of the complementary 
rose-red hue, the effect is supposed to be due to a 
temporary fatigue of the retina in relation to those 
ingredients of the total light in the second case which 
answer to the partial light in the first (the green rays). 2 

These momentary modifications of sensibility are 

1 Helmlioltz, op. cit., p. 600, el seq. These facts seem to point to the 
conclusion that at least some of the feelings by which we know that 
we are expending muscular energy are connected with the initial stage 
of the outgoing nervous process in the motor centres. In other 
pathological conditions the sense of weight by the muscles of the arms 
is similarly confused. 

2 Wundt (Physiologisclie Psyclwlogie, p. C53) would exclude from 
illusions all those errors of sense-perception which have their foun- 
dation in the normal structure and function of the organs of sense. 
Thus, he would exclude the effects of colour-contrast, e.g. the 
apparent modification of two colours in juxtaposition towards their 
common boundary, which probably arises (according to E. Herin?) 
from some mutual influence of the temporary state of activity of 
adjacent retinal elements. To me, however, these appear to be 
illusions, since they may be brought under the head of wrong inter- 
pretations of sense-impressions. When we see a grey patch as 
rose-red, as though it were so independently of the action of the com- 
plementary light previously or simultaneously, that is to say, as 
though it would appear rose-red to an eye independently of this 
action, we surely misinterpret. 



68 ILLUSIONS OF PERCEPTION. 

of no practical significance, being almost instantly 
corrected. Other modifications are more permanent- 
It was found by Himly that when the retina is over- 
excitable every stimulus is raised in the spectrum scale 
of colours. Thus, violet becomes red. An exactly 
opposite effect is observed when the retina is torpid. 1 
Certain poisons are known to affect the quality of the 
colour-impression. Thus, santonin, when taken in any 
quantity, makes all colourless objects look yellow. 
Severe pathological disturbances are known to involve, 
in addition to hypersesthesia and anaesthesia, what has 
been called paresthesia, that is to say, that condition 
in which the quality of sensation is greatly changed. 
Thus, for example, to one in this state all food appears 
to have a metallic taste, and so on. 

If we now glance back at the various groups of 
illusions just illustrated, we find that they all have 
this feature in common : they depend *on the general 
mental law that when we have to do with the unfre- 
quent, the unimportant, and therefore unattended to, 
and the exceptional, we employ the ordinary, the 
familiar, and the well-known as our standard. Thus, 
whether we are dealing with sensations that fall below 
the ordinary limits of our mental experience, or with 
those which arise in some exceptional state of the 
organism, we carry the habits formed in the much 
wider region of average every-day perception with. us. 
In a word, illusion in these cases always arises through • 
what may, figuratively at least, be described as the 
application of a rule, valid for the majority of cases, 
to an exceptional case. 

1 Quoted by G. H. Lewes, loc. cit., p. 257 



ILLUSION AND HABIT. 69 

In the varieties of illusion just considered, the 
circumstance that gives the peculiarity to the case 
thus wrongly interpreted has been referred to the 
organism. In the illusions to which we now pass, it 
will be referred to the environment. At the same 
time, it is plain that there is no very sharp distinction 
between the two classes. Thus, the visual illusion pro- 
duced by pressing the eyeball might be regarded not 
only as the result of the organic law of the " specific 
energy " of the nerves, but, with almost equal appro- 
priateness, as the consequence of an exceptional state 
of things in the environment, namely, the pressure 
of a body on the retina. As I have already observed, 
the classification here adopted is to be viewed simply 
as a rough expedient for securing something like a 
systematic review of the phenomena. 



vm 



CHAPTER V. 

illusions of perception — continued. 

A. Passive Illusions (h) as determined by the 
Environment. 

In the following groups of illusion we may look away 
from nervous processes and organic disturbances, 
regarding the effect of any external stimulus as cha- 
racteristic, that is, as clearly marked off from the 
effects of other stimuli, and as constant for the same 
stimulus. The source of the illusion will be looked 
for in something exceptional in the external circum- 
stances, whereby one object or condition of an object 
imitates the effect of another object or condition, to 
which, owing to a large preponderance of experience, 
we at once refer it. 

Exceptional Relation of Stimulus to Organ. 

A transition from the preceding to the following 
class of illusions is to be met with in those errors 
which arise from a very exceptional relation between 
the stimulus and the organ of sense. Such a state 
of things is naturally interpreted by help of more 
common and familiar relations, and so error arises. 



DISPLACEMENT OF ORGAN. 71 

For example, we may grossly misinterpret the 
intensity of a stimulus under certain circumstances. 
Thus, when a man crunches a biscuit, he has an un- 
comfortable feeling that the noise as of all the struc- 
tures of his head being violently smashed is the same 
to other ears, and he may even act on his illusory per- 
ception, by keeping at a respectful distance from all 
observers. And even though he be a physiologist, 
and knows that the force of sensation in this case is 
due to the propagation of vibrations to the auditory 
centre by other channels than the usual one of the ear, 
the deeply organized impulse to measure the strength 
of an external stimulus by the intensity of the sensa- 
tion asserts its force. 

Again, if we turn to the process of perceptional 
construction properly so called, the reference of the 
sensation to a material object lying in a certain direc- 
tion, etc., we find a similar transitional form of illusion. 
The most interesting case of this in visual perception 
is that of a disturbance or displacement of the organ 
by external force. For example, an illusory sense of 
direction arises by the simple action of closing one 
eye, say the left, and pressing the other eyeball with 
one of the fingers a little outwards, that is to the right. 
The result of this movement is, of course, to transfer 
the retinal picture to new nervous elements further 
to the right. And since, in this instance, the dis- 
placement is not produced in the ordinary way by 
the activity of the ocular muscle making itself known 
by certain feelings of movement, it is disregarded 
altogether, and the direction of the objects is judged 
as though the eye were stationary. 



72 ILLUSIONS OF PERCEPTION. 

A somewhat similar illusion as to direction occurs 
in auditory perception. The sense of direction by the 
ear is known to be due in part to the action of the 
auricle, or projecting part of the ear. This collects 
the air-waves, and so adds to the intensity of the 
sounds, especially those coming from in front, and 
thus assists in the estimation of direction. This being 
so, if an artificial auricle is placed in front of the ears ; 
if, for example, the two hands are each bent into a 
sort of auricle, and placed in front of the ears, the 
back of the hand being in front, the sense of direction 
(as well as of distance) is confused. Thus, sounds 
really travelling from a point in front of the head will 
appear to come from behind it. 

Again, the perception of the unity of an object is 
liable to be falsified by the introduction of exceptional 
circumstances into the sense-organ. This is illustrated 
in the well-known experiment of crossing two fingers, 
say the third and fourth, and placing a marble or other 
small round object between them. Under ordinary cir- 
cumstances, the two lateral surfaces (that is, the outer 
surfaces of the two fingers) now pressed by the marble^ 
can only be acted on simultaneously by two objects 
having convex surfaces. Consequently, we cannot 
help feeling the presence of two objects in this ex- 
ceptional instance. The illusion is analogous to that 
of the stereoscope, to be spoken of presently. 

Exceptional External Arrangements. 

Passing now to those cases where the exceptional 
circumstance is altogether exterior to the organ, we 
find a familiar example in the illusions connected with 



DIEECTION AND MOVEMENT. io 

the action of well-known physical forces, as the re- 
fraction of light, and the reflection of light and 
sound. A stick half-immersed in water always looJcs 
broken, however well we may know that the appear- 
ance is due to the bending of the rays of light. 
Similarly, an echo always sounds as though it came 
from some object in the direction in which the air- 
waves finally travel to the ear, though we are perfectly 
sure that these undulations have taken a circuitous 
course. It is hardly necessary to remind the reader 
that the deeply organized tendency to mistake the 
direction of the visible or audible object in these cases 
has from remote ages been made use of as a means of 
popular delusion. Thus, we are told by Sir D. Brewster, 
in his entertaining Letters on Natural Magic (letter 
iv.), that the concave mirror was probably used as the 
instrument for bringing the gods before the people. 
The throwing of the images formed by such mirrors 
upon smoke or against fire, so as to make them more 
distinct, seems to have been a favourite device in the 
ancient art of necromancy. 

Closely connected with these illusions of direction 
with respect to resting objects, are those into which we 
are apt to fall respecting the movements of objects. 
What looks like the movement of something across 
the field of vision is made known to us either by the 
feeling of the ocular muscles, if the eye follows the 
object, or through the sequence of locally distinct 
retinal impressions, if the eye is stationary. Now, 
either of these effects may result, not only from the 
actual movement of the object in a particular direc- 
tion, but from our own movement in an opposite 



<4 ILLUSIONS OF PERCEPTION". 

direction ; or, again, from our both moving in the first 
direction, the object more rapidly than ourselves; or, 
finally, from our both moving in an opposite direction 
to this, ourselves more rapidly than the object. There 
is thus always a variety of conceivable explanations, 
and the action of past experience and association 
shows itself very plainly in the determination of the 
direction of interpretation. Thus, it is our instinctive 
tendency to take apparent movement for real move- 
ment, except when the fact of our own movement is 
clearly present to consciousness, as when we are walk- 
ing, or when we are sitting behind a horse whose 
movement we see. And so when the sense of our own 
movement becomes indistinct, as in a railway carriage, 
we naturally drift into the illusion that objects, such as 
trees, telegraph posts, and so on, are moving, when they 
are perfectly still. Under the same circumstances, we 
are apt to suppose that a train which is just shooting 
ahead of us is moving slowly. 

Similar uncertainties arise with respect to the 
relative movement of two objects, the eye being sup- 
posed to be fixed in space. When two objects seem 
to pass one another, it may be that they are both 
moving in contrary directions, or that one only is 
moving, or finally, that both are moving in the same 
direction, the one faster than the other. Experience 
and habit here again suggest the interpretation which 
is most easy, and not unfrequently produce illusion. 
Thus, when we watch clouds scudding over the face of 
the moon, the latter seems moving rather than the 
former, and the illusion only disappears when we fix 
the eye on the moon and recognize that it is really 



ILLUSIONS OF DISTANCE. 75 

stationary. The probable reason of this is, as Wundt 
suggests, that experience has made it far easier for us 
to think of small objects like the moon moving rapidly, 
than of large masses like the clouds. 1 

The perception of distance, still more than that of 
direction, is liable to be illusory. Indeed, the visual 
recognition of distance, together with that of solidity, 
has been the great region for the study of " the decep- 
tions of the senses." Without treating the subject 
fully here, I shall try to describe briefly the nature 
and source of these illusions. 2 

Confining ourselves first of all to near objects, we 
know that the smaller differences of distance in these 
cases are, if the eyes are at rest, perceived by means of 
the dissimilar pictures projected on the two retinas ; or 
if they move, by this means, together with the muscular 
feelings that accompany different degrees of converg- 
ence of the two eyes. This was demonstrated by the 
famous experiments of Wheatstone. Thus, by means 
of the now familiar stereoscope, he was able to produce 
a perfect illusion of relief. The stereoscope may be 

1 The subject of the perception of movement is too intricate to be 
dealt with fully here. I have only touched on it so far as necessary to 
illustrate our general principle. For a fuller treatment of the 
subject, see the work of Dr. Hoppe, already referred to. 

8 The perception of magnitude is closely connected with that of 
distance, and is similarly apt to take an illusory form. I need only 
refer to the well-known simple ojDtical contrivances for increasing the 
apparent magnitude of objects. I ought, perhaps, to add that I do not 
profess to give a complete account of optical illusions here, but only to 
6elect a few prominent varieties, with a view to illustrate general prin- 
ciples of illusion. For a fuller account of the various mechanical 
arrangements for producing optical illusion, I must refer the reader to 
the writings of Sir D. Brewster and Helmholtz. 



7b ILLUSIONS OF PERCEPTION. 

said to introduce an exceptional state of things into the 
spectator's environment. It imitates, by means of two 
flat drawings, the dissimilar retinal pictures projected 
by a single solid receding object, and the lenses through 
which the eyes look are so constructed as to compel 
them to converge as though looking on a single object. 
And so powerful is the tendency to interpret this im- 
pression as one of solidity, that even though we are 
aware of the presence of the stereoscopic apparatus, 
we cannot help seeing the two drawings as a single 
solid object. 

In the case of more remote objects, there is no 
dissimilarity of the retinal pictures or feelings of con- 
vergence to assist the eye in determining distance. 
Here its judgment, which now becomes more of a pro- 
cess of conscious inference, is determined by a number 
of circumstances which, through experience and asso- 
ciation, have become the signs of differences of depth 
in space. Among these are the degree of indistinctness 
of the impression, the apparent or retinal magnitude (if 
the object is a familiar one), the relations of linear per- 
spective, as the interruption of the outline of far objects 
by that of near objects, and so on. In a process so com- 
plicated there is clearly ample room for error, and wrong 
estimates of distance whenever unusual circumstances 
are present are familiar to all. Thus, the inexperienced 
English tourist, when in the clear atmosphere of Swit- 
zerland, where the impressions from distant objects are 
more distinct than at home, naturally falls into the 
illusion that the mountains are much nearer than they 
are, and so fails to realize their true altitude. 



JUDGING DISTANCE. 77 

Illusions of Art. 

The imitation of solidity and depth by art is a 
curious and interesting illustration of the mode of 
production of illusion. Here we are not, of course, 
concerned with the question how far illusion is desir- 
able in art, but only with its capabilities of illusory 
presentment ; which capabilities, it may be added, 
have been fully illustrated in the history of art. The 
full treatment of this subject would form a chapter in 
itself; here I can only touch on its main features. 

Pictorial art working on a flat surface cannot, it is 
plain, imitate the stereoscope, and produce a perfect 
sense of solidity. Yet it manages to produce a pretty 
strong illusion. It illustrates in a strikino; manner 
the ease with which the eye conceives relations of 
depth or relief and solidity. If, for example, on 
a carpet, wall-paper, or dress, bright lines are laid on a 
dark colour as ground, we easily imagine that they are 
advancing. The reason of this seems to be that in our 
daily experience advancing surfaces catch and reflect 
the light, whereas retiring surfaces are in shadow. 1 

The same principle is illustrated in one of the 
means used by the artist to produce a strong sense 
of relief, namely, the cast shadow. A circle drawn 
with chalk with a powerful cast shadow on one side 

1 Painters are well aware that the colours at the red end of the 
spectrum are apt to appear as advancing, while those of the violet end 
are known as retiring. The appearance of relief given by a gilded 
pattern on a dark blue as ground, is in part referable to the principle 
just referred to. In addition, it appears to involve a difference in the 
action of the muscles of accommodation in the successive adaptations 
of the eye to the most refrangible and the least refrangible rays. 
(See Briicke, Die Physiologie der Farben, sec. 17.) 



78 



ILLUSIONS OF PERCEPTION. 



will, without any shading or modelling of the form, ap- 
pear to stand out from the paper, thus : 




Fig. 1. 

The reason is that the presence of such a shadow so 
forcibly suggests to the mind that the object is a pro- 
minent one intervening between the light and the 
shaded surface. 1 

Even without differences of light and shade, by a 
mere arrangement of lines, we may produce a powerful 
sense of relief or solidity. A striking example of 
this is the way in which two intersecting lines some- 
times appear to recede from the eye, as the lines a a', 
b &', in the next drawing, which seem to belong to a 
regular pattern on the ground, at which the eye is 
looking from above and obliquely. 

b' 




Fig. 2. 



1 Helmholtz tells us (Populate tvissenschaftliche Vorlrage, 3tes 
Heft, p. 64) that even in a stereoscopic arrangement the presence 
of a wrong cast shadow sufficed to disturb the illusion. 



ART AND RELIEF. 



79 



Again, the correct delineation of the projection of a 
regular geometrical figure, as a cube, suffices to give 
the eye a sense of relief. This effect is found to be 
the more striking in proportion to the familiarity of 
the form. The following drawing of a long box-shaped 
solid at once seems to stand out to the eye. 




Fig. 3. 

This habitual interpretation of the flat in art as 
answering to objects in relief, or having depth, can 
only be understood when it is remembered that our 
daily experience gives us myriads of instances in 
which the effect of such flat representations answers 
to solid receding forms. That is to say, in the case 
of all distant objects, in the perception of which the 
dissimilarity of the retinal pictures and the feeling 
of convergence take no part, we have to interpret 
solidity, and relations of nearer and further, by such 
signs as linear perspective and cast shadow. On 
the other hand, it is only in the artificial life 
of indoors, on our picture-covered walls, that we ex- 
perience such effects without discovering corresponding 
realities. Hence a deeply organized habit of taking 
these impressions as answering to the solid and not to 
the flat. If our experience had been quite different : 



80 



ILLUSIONS OF PERCEPTION. 



if, for example, we had been brought up in an empty 
room, amid painted walls, and had been excluded from 
the sight of the world of receding objects outside, we 
might easily have formed an exactly opposite habit of 
taking the actual mountains, trees, etc., of the distant 
scene to be pictures laid on a flat surface. 

It follows from this that, with respect to the distant 
parts of a scene, pictorial art possesses the means of 
perfect imitation ; and here we see that a complete 
illusory effect is obtainable. I need but to refer to 
the well-known devices of linear and aerial perspective, 
by which this result is secured. 1 The value of these 
means of producing illusion at the command of the 
painter, may be illustrated by the following fact, which 
I borrow from Helmholtz. If you place two pieces of 




Pig. 4. 



cardboard which correspond to portions of one form at 
the sides and in front of a third piece, in the way 
represented above, so as just to allow the eye to follow 
the contour of this last, and then look at this arrange- 

1 Among the means of giving a vivid sense of depth to a picture, 
emphasized by Helmholtz, is diminishing magnitude. It is obvious 
that the perceptions of real magnitude and distance are mutually 
involved. When, for example, a picture represents a receding series 
of objects, as animals, tiees, or buildings, the sense of the third 
dimension is rendered much more clear. 



PICTOBIAL DELUSION. 81 

ment from a point at some little distance with one eye, 
you easily suppose that it stands in front of the side 
pieces. The explanation of the illusion is that this 
particular arrangement powerfully suggests that the 
outline of the whole figure, of which the two side 
pieces are parts, is broken by an intervening object. 
Owing to the force of the s se and other suggestions, 
it is easy for the spectator, when attending to the back- 
ground of a landscape painting, to give himself up 
for a moment to the pleasant delusion that he is looking 
at an actual receding scene. 

In connection with pictorial delusion, I may refer 
to the well-known fact, that the eye in a portrait 
seems to follow the spectator, or that a gun, with its 
muzzle pointing straight outwards, appears to turn as 
the spectator moves. 1 These tricks of art have puzzled 
many people, yet their effect is easily understood, and 
has been very clearly explained by Sir D. Brewster, in 
the work already referred to (letter v.). They depend 
on the fact that a painting, being a flat projection only 
and not a solid, continues to present the front view of 
an object which it represents wherever the spectator 
happens to stand. Were the eye in the portrait a real 
eye, a side movement of the spectator would, it is 
evident, cause him to see less of the pupil and more 
of the side of the eyeball, and he would only con- 
tinue to see the full pupil when the eye followed 
him. We regard the eye in the picture as a real eye 
having relief, and judge accordingly. 

1 A striking example of this was given in a painting, by Andsell, 
of a sportsman in llie act of shooting, exhibited in the Boyal Academy 
in 1879. 

5 



82 ILLUSIONS OF PERCEPTION. 

We may fall into similar illusions respecting dis- 
tance in auditory perception. A change of wind, an 
unusual stillness in the air, is quite sufficient to produce 
the sense that sounding objects are nearer than they 
actually are. The art of the ventriloquist manifestly 
aims at producing this kind of illusion. By imitating 
the dull effect of a distant voice, he is able to excite 
in the minds of his audience a powerful conviction that 
the sounds proceed from a distant point. There is 
little doubt that ventriloquism has played a con- 
spicuous part in the arts of divination and magic. 

Misconception of Local Arrangement. 

Let us now pass to a class of illusions closely related 
to those having to do with distance, but involving some 
special kind of circumstance which powerfully suggests 
a particular arrangement in space. One of the most 
striking examples of these is the erroneous localization 
of a quality in space, that is to say, the reference of it 
to an object nearer or further off than the right one. 
Thus, when we look through a piece of yellow glass at 
a dull, wintry landscape, we are disposed to imagine 
that we are looking at a sunny scene of preternatural 
warmth. A moment's reflection would tell us that the 
yellow tint, with which the objects appear to be 
suffused, comes from the presence of the glass ; yet, in 
spite of this, the illusion persists with a curious force. 
The explanation is, of course, that the circumstances 
are exceptional, that in a vast majority of cases the 
impression of colour belongs to the object and not to 
an intervening medium, 1 and that consequently we 

1 This is at hast true of all near objects. 



OBJECTS AND COLOURED MEDIA. 83 

tend to ignore the glass, and to refer the colour to the 
objects themselves. 

When, however, the fact of the existence of a 
coloured medium is distinctly present to the mind, we 
easily learn to allow for this, and to recognize one 
coloured surface correctly through a recognized medium. 
Thus, we appear to ourselves to see the reflected images 
of the wall, etc., of a room, in a bright mahogany table, 
not suffused with a reddish yellow tint, as they actually 
are — and may be seen to be by the simple device 
of looking at a small bit of the image through a tube, 
but in their ordinary colour. We may be said to fall 
into illusion here in so far as we overlook the exact 
quality of the impression actually made on the eye. 
This point will be touched on presently. Here I am 
concerned to show that this habit of allowing for the 
coloured medium may, in its turn, occasionally lead to 
plain and palpable illusion. 

The most striking example of this error is to be met 
with among the curious phenomena of colour-contrast 
already referred to. In many of these cases the appear- 
ance of the contrasting colour is, as I have observed, 
due to a temporary modification of the nervous sub- 
stance. Yet it is found that this organic factor does 
not wholly account for the phenomena. For example, 
Meyer made the following experiment. He covered a 
piece of green paper by a sheet of thin transparent 
white paper. The colour of this double surface was, of 
course, a pale green. He then introduced a scrap of 
grey paper between the two sheets, and found that, in- 
stead of looking whitish as it really was, it looked rose- 
red. Whatever the colour of the under sheet the grey 



84 ILLUSIONS OF PEKCEPTION. 

scrap took the complementary hue. If, however, the 
piece of grey paper is put outside the thin sheet, it 
looks grey ; and what is most remarkable is that when 
a second piece is put outside, the scrap inside no longer 
wears the complementary hue. 

There is here evidently something more than a 
change of organic conditions ; there is an action of 
experience and suggestion. The reason of our seeing 
the scrap rose-red in one case and neutral grey in 
another, is that in the first instance we vividly repre- 
sent to ourselves that we are looking at it through a 
greenish veil (which is, of course, a part of the illusion) ; 
for rose-red seen through a greenish medium would, as 
a matter of fact, be light grey, as this scrap is. Even 
if we allow that there always exists after an impression 
of colour a temporary organic disposition to see the 
complementary hue, this does not suffice as an expla- 
nation of these cases ; we have to conclude further that 
imagination, led by the usual run of our experience, 
is here a co-operant factor, and helps to determine 
whether the complementary tint shall be seen or not. 

Misinterpretation of Form. 

More complex and circumscribed associations take 
part in those errors which we occasionally commit re- 
specting the particular form of objects. This has already 
been touched on in dealing with artistic illusion. The 
disposition of the eye to attribute solidity to a flat 
drawing is the more powerful in proportion to the 
familiarity of the form. Thus, an outline drawing of a 
building is apt to stand out with special force. 

Another curious illustration of this is the pheno- 



CONVERSION OF CONCAVE FORM. 85 

menon known as the conversion of the concave mould or 
matrix of a medal into the corresponding convex relief. 
If, says Helmholtz, the mould of a medal be illuminated 
by a light falling obliquely so as to produce strong- 
shadows, and if we regard this with one eye, we easily 
fall into the illusion that it -is the original raised 
design, illaminated from the opposite side. As a matter 
of fact, the visual impression produced by a concave 
form with the light falling on one side, very closely 
resembles that produced by a corresponding convex 
form with the light falling on the other side. At the 
same time, it is found that the opposite mode of con- 
version, that is to say, the transformation of the raised 
into the depressed form, though occurring occasionally, 
is much less frequent. Now, it may be asked, why 
should we tend to transform the concave into the con- 
vex, rather than the convex into the concave ? The 
reader may easily anticipate the answer from what 
has been said about the deeply fixed tendency of 
the eye to solidify a plane surface. We are rendered 
much more familiar, both by nature and by art, with 
raised (cameo) design than with depressed design (in- 
taglio), and we instinctively interpret the less familiar 
form by the more familiar. This explanation appears 
to be borne out by the fact emphasized by Schroeder 
that the illusion is much more powerful if the design 
is that of some well-known object, as the human head 
or figure, or an animal form, or leaves. 1 

1 Helmholtz remarks (op. cit, p. G28) that the difficulty of seeing 
the cob vex cast as concave is probably clue to the presence of the 
cast shadow. This has, no doubt, some effect : yet the consideration 
urged in the test appears to me to be the most important one. 



86 ILLUSIONS OF PERCEPTION. 

Another illustration of this kind of illusion recently 
occurred in my own experience. Nearly opposite to 
my window came a narrow space between two detached 
houses. This was, of course, darker than the front of 
the houses, and the receding parallel lines of the bricks 
appeared to cross this narrow vertical shaft obliquely. 
I could never look at this without seeing it as a convex 
column, round which the parallel lines wound obliquely. 
Others saw it as I did, though not always with the 
same overpowering effect. I can only account for this 
illusion by help of the general tendency of the eye to 
solidify impressions drawn from the flat, together with 
the effect of special types of experience, more par- 
ticularly the perception of cylindrical forms in trees, 
columns, etc. 

It may be added that a somewhat similar illustra- 
tion of the action of special types of experience on the 
perception of individual form may be found in the 
region of hearing. The powerful disposition to take 
the finely graduated cadences of sound produced by 
the wind for the utterances of a human voice, is due 
to the fact that this particular form and arrangement 
of sound has deeply impressed itself on our minds, in 
connection with numberless utterances of human 
feeling. 

Illusions of Recognition. 

As a last illustration of comparatively passive 
illusions, I may refer to the errors which we occasion- 
ally commit in recognizing objects. As I have already 
observed, the process of full and clear recognition, 
specific ajid individual, involves a classing of a number 



FALSE RECOGNITION. 87 

of distinct aspects of the object, such as colour, form, 
etc. Accordingly, when in a perfectly cairn state of 
mind we fall into illusion with respect to any object 
plainly visible, it must be through some accidental 
resemblance between the object and the other object or 
class of objects with which we identify it. In the 
<^ase of individual identification such illusions are, of 
course, comparatively rare, since here there are in- 
volved so many characteristic differences. On the 
other hand, in the case of specific recognition there is 
ample room for error, especially in those kinds of more 
subtle recognition to which I have already referred. 
To " recognize " a person as a Frenchman or a military 
man, for example, is often an erroneous process. Logi- 
cians have included this kind of error under what 
they call " fallacies of observation." 

Errors of recognition, both specific and individual, 
are, of course, more easy in the case of distant objects or 
objects otherwise indistinctly seen. It is noticeable in 
these cases that, even when perfectly cool and free 
from emotional excitement, we tend to interpret such 
indistinct impressions according to certain favourite 
types of experience, as the human face and figure. Our 
interpretative imagination easily sees traces of the 
human form in cloud, rock, or tree-stump. 

Again, even when there is no error of recognition, 
in the sense of confusing one object with other objects, 
there may be partial illusion. I have remarked that 
the process of recognizing an object commonly involves 
an overlooking of points of diversity in the object, or 
aspect of the object, now present. And sometimes this 
:„„ ++ „^+; „ 4-^ ,„i^+ ^ actual Iv present includes an er>*^ v 



88 ILLUSIONS OP PERCEPTION. 

as to the actual visual sensation of the moment. Thus, 
for example, when I look at a sheet of white paper in 
a feebly lit room, I seem to see its whiteness. If, how- 
ever, I bring it near the window, and let the sun fall 
on a part of it, I at once recognize that what I have 
been seeing is not white, but a decided grey. Similarly, 
when I look at a brick viaduct a mile or two off, I 
appear to myself to recognize its redness. In fact, 
however, the impression of colour which I receive from 
the object is not that of brick-red at all, but a much 
less decided tint ; which I may easily prove by bending 
my head downwards and letting the scene image itself 
on the retina in an unusual way, in which case the 
recognition of the object as a viaduct being less dis- 
tinct, I am better able to attend to the exact shade of 
the colour. 

Nowhere is this inattention to the sensation of the 
moment exhibited in so striking a manner as in 
pictorial art. A picture of Meissonier may give the 
eye a representation of a scene in which the objects, as 
the human figures and horses, have a distinctness that 
belongs to near objects, but an apparent magnitude 
that belongs to distant objects. So again, it is found 
that the degree of luminosity or brightness of a pic- 
torial representation differs in general enormously from 
that of the actual objects. Thus, according to the cal- 
culations of Helmholtz, 1 a picture representing a Be- 
douin's white raiment in blinding sunshine, will, when 
seen in a fairly lit gallery, have a degree of lumi- 
nosity reaching only to about one-thirtieth of that 
of the actual object. On the other hand, a painting 

1 Fopulare wissenecliaftliche Vortrage, Stes Heft, pp. 71, 72. 



SENSATION OVERPOWERED BY SUGGESTION. 89 

representing marble ruins illuminated by moonlight, 
will, under the same conditions of illumination, have a 
luminosity amounting to as much as from ten to twenty 
thousand times that of the object. Yet the spectator 
does not notice these stupendous discrepancies. The 
representation, in spite of its vast difference, at once 
carries the mind on to the actuality, and the spectator 
may even appear to himself, in moments of complete 
absorption, to be looking at the actual scene. 

The truly startling part of these illusions is, that 
the direct result of sensory stimulation appears to he 
actually displaced by a mental image. Thus, in the 
case of Meyer's experiment, of looking at the distant 
viaduct, and of recognizing an artistic representation, 
imagination seems in a measure to take the place of 
sensation, or to blind the mind to what is actually 
before it. 

The mystery of the process, however, greatly dis- 
appears when if is remembered that what we call a 
conscious " sensation " is really compounded of a result 
of sensory stimulation and a result of central reaction, 
of a purely passive impression and the mental activity 
involved in attending to this and classing it. 1 This 
being so, a sensation may be modified by anything 
exceptional in the mode of central reaction of the 
moment. Now, in all the cases just considered, we 
have one common feature, a powerful suggestion of 
the presence of a particular object or local arrange- 
ment. This suggestion, taking the form of a vivid 
mental image, dominates and overpowers the passive 

1 Sec, on this point, some excellent remarks by G. H. Lewes, 
Problems of Life and Mind, third series, vol. ii. p. 275. 



90 ILLUSIONS OF PEECEPTION. 

impression. Thus, in Meyer's experim ent, the mind is 
possessed by the supposition that we are looking at the 
grey spot through a greenish medium. So in the case 
of the distant viaduct, we are under the mastery of the 
idea that what we see in the distance is a red brick 
structure. Once more, in the instance of looking at 
the picture, the spectator's imagination is enchained by 
the vivid representation of the object for which the 
picture stands, as the marble ruins in the moonlight or 
the Bedouin in the desert. 

It may be well to add that this mental uncertainty 
as to the exact nature of a present impression is neces- 
sitated by the very conditions of accurate perception. 
If, as I have said, all recognition takes place by over- 
looking points of diversity, the mind must, in course of 
time, acquire a habit of not attending to the exact 
quality of sense-impressions in all cases where the 
interpretation seems plain and obvious. Or, to use 
Helmholtz's words, our sensations are, in a general way, 
of interest to us only as signs of things, and if we are 
sure of the thing, we readily overlook the precise nature 
of the impression. In short, we get into the way 
of attending only to what is essential, constant, and 
characteristic in objects, and disregarding what is 
variable and accidental. 1 Thus, we attend, in the first 
place, to the form of objects, the most constant and 
characteristic element of all, being comparatively 

1 To some extent this applies to the changes of apparent magni- 
tude due to altered position. Thus, we do not attend to the reduction 
ol the height of a small object which we are wont to handle, when it is 
placed far below the level of the eye. And hence the error peoj.le 
make in judging of the point in the wall or skirting which a hat will 
reach when placed on the ground. 



RECOGNITION AS INATTENTION. 91 

inattentive to colour, which varies with distance, atmo- 
spheric changes, and mode of illumination. So we 
attend to the relative magnitude of objects rather than 
to the absolute, and to the relative intensities of light 
and shade rather than to the absolute ; for in so doing 
we are noting what is constant for all distances and 
modes of illumination, and overlooking what is variable. 
And the success of pictorial art depends on the ob- 
servance of this law of perception. 

These remarks at once point out the limits of these 
illusions. In normal circumstances, an act of imagi- 
nation, however vivid, cannot create the semblance of 
a sensation which is altogether absent ; it can only 
slightly modify the actual impression by interfering 
with that process of comparison and classification 
which enters into all definite determination of sensa- 
tional quality. 

Another great fact that has come to light in the 
investigation of these illusions is that oft-recurring and 
familiar types of experience leave permanent disposi- 
tions in the mind. As I said when describing the pro- 
cess of perception, what has been frequently perceived 
is perceived more and more readily. It follows from 
this that the mind will be habitually disposed to form 
the corresponding mental images, and to interpret 
impressions by help of these. The range of artistic 
suggestion depends on this. A clever draughtsman 
can indicate a face by a few rough touches, and this 
is due to the fact that the spectator's mind is so 
familiarized, through recurring experience and special 
interest, with the object, that it is ready to construct 
the requisite mental image at the slightest external 



92 ILLUSIONS OF PERCEPTION. 

suggestion. And hence the risk of hasty and illusory 
interpretation. 

These observations naturally conduct us to the 
consideration of the second great group of sense- 
illusions, which I have marked off as active illusions, 
where the action of a pre-existing intellectual dis- 
position becomes much more clearly marked, and 
assumes the form of a free imaginative transformation 
of reality. 



CHAPTER YL 
illusions of perception — continued. 

B. Active Illusions. 

When giving an account of the mechanism of percep- 
tion, I spoke of an independent action of the imagina- 
tion which tends to anticipate the process of suggestion 
from without. Thus, when expecting a particular 
friend, I recognize his form much more readily than 
when my mind has not been preoccupied with his 
image. 

A little consideration will show that this process 
must be highly favourable to illusion. To begin 
with, eyen if the preperception be correct, that is 
to say, if it answer to the perception, the mere fact 
of vivid expectation will affect the exact moment of 
the completed act of perception. And recent experi- 
ment shows that in certain cases such a previous activity 
of expectant attention may even lead to the illusory 
belief that the perception takes place before it actually 
does. 1 

1 I refer to the experiments made by Exnur, Wundt, and others, in 
determining the time elapsing between the giving of a signal to a 



94 ILLUSIONS OF PERCEPTION. 

A more palpable source of error resides in the risk 
of the formation of an inappropriate preperception. If 
a wrong mental image happens to have been formed 
and vividly entertained, and if the actual impression 
fits in to a certain extent with, this independently 
formed preperception, we may have a fusion of the 
two which exactly simulates the form of a complete 
percept. Thus, for example, in the case just supposed, 
if another person, bearing some resemblance to our 
expected friend, chances to come into view, we may 
probably stumble into the error of taking one person 
for another. 

On the physical side, we may, agreeably to the 
hypothesis mentioned above, express this result by 
saying that, owing to a partial identity in the nervous 
processes involved in the anticipatory image and the 
impression, the two tend to run one into the other, con- 
stituting one continuous process. 

There are different ways in which this independent 
activity of the imagination may falsify our perceptions. 
Thus, we may voluntarily choose to entertain a certain 
image for the moment, and to look at the impression 
in a particular way, and within certain limits such capri- 
cious selection of an interpretation is effectual in giving 
a special significance to an impression. Or the process 
of independent preperception may go on apart from our 
volitions, and perhaps in spite of these, in which case 
the illusion has something of the irresistible necessity 

person and the execution of a movement in response. " It is found," 
Bays Wundt, " by these experiments that the exact moment at which 
a sense-impression is perceived depends on the amount of preparatory 
6elf-accommodation of attention." (See Wundt, Physiuloginche Psycho- 
logies ch. xix., especially p. 735. et seq. ) 



PRE-PERCEPTTON AND ILLUSION. 95 

of a passive illusion. Let us consider separately each 
mode of production. 

Voluntary Selection of Interpretation. 

The action of a capricious exercise of the imagina- 
tion in relation to an impression is illustrated in those 
cases where experience and suggestion offer to the 
interpreting mind an uncertain sound, that is to say, 
where the present sense-signs are ambiguous. Here 
we obviously have a choice of interpretation. And it 
is found that, in these cases, what we see depends 
very much on what we wish to see. The interpre- 
tation adopted is still, in a sense, the result of sug- 
gestion, but of one particular suggestion which the 
fancy of the moment determines. Or, to put it 
another way, the caprice of the moment causes the 
attention to focus itself in a particular manner, to 
direct itself specially to certain aspects and relations of 
objects. 

The eye's interpretation of movement, already 
referred to, obviously offers a wide field for this play of 
selective imagination. When looking out of the win- 
dow of a railway carriage, I can at will picture to my 
mind the trees and telegraph posts as moving objects. 
Sometimes the true interpretation is so uncertain that 
the least inclination to view the phenomenon in one 
way determines the result. This is illustrated in a 
curious observation of Sinsteden. One evening, on 
approaching a windmill obliquely from one side, which 
under these circumstances he saw only as a dark 
silhouette against a bright sky, he noticed that the 
sails appeared to go, now in one direction, now in 



96 ILLUSIONS OF PERCEPTION. 

another, according as he imagined himself looking at 
the front or at the back of the windmill. 1 

In the interpretation of geometrical drawings, as 
those of crystals, there is, as I have observed, a general 
tendency to •view the flat delineation as answering to a 
raised object, or a body in relief, according to the com- 
mon run of our experience. Yet there are cases where 
experience is less decided, and where, consequently, we 
may regard any particular line as advancing or reced- 
ing. And it is found that when we vividly imagine 
that the drawing is that of a convex or concave surface » 
we see it to be so, with all the force of a complete per- 
ception. The least disposition to see it in the other 
way will suffice to reverse the interpretation. Thus, 
in the following drawing, the reader can easily see at 




Fig. 5. 

will something answering to a truncated pyramid, or 
to the interior of a cooking vessel. 

Similarly, in the accompanying figure of a trans- 
parent solid, I can at will select either of the two 
surfaces which approximately face the eye and regard 

1 Quoted by Helmholtz, op. cit., p. 626. 



VISUAL SELECTION OF FORM. 



97 



it as the nearer, the other appearing as the hinder 
surface looked at through the body. 



Fig. 6. 

Again, in the next drawing, taken from Schroeder, 
one may, by an effort of will, see the diagonal step-like 
pattern, either as the view from above of the edge of 
an advancing piece of wall at a, or as the view from 
below of the edge of an advancing (overhanging) piece 
of wall at b. 




Fig. 7. 

These last drawings are not in true perspective on 
either of the suppositions adopted, Avherefore the choice 
is easier. But even when an outline form is in per- 
spective, a strenuous effort of imagination may suffice 
to bring about a conversion of the appearance. Thus, 
if the reader will look at the drawing of the box-like 
solid (Fig. 3, p. 79), he will find that, after a trial or 



98 ILLUSIONS OF PERCEPTION 

two, he succeeds in seeing it as a concave figure repre- 
senting the cover and two sides of a box as looked at 
from within. 1 

Many of my readers, probably, share in my power 
of variously interpreting the relative position of bands 
or stripes on fabrics such as wall-papers, according 
to wish. I find that it is possible to view now this 
stripe or set of stripes as standing out in relief upon 
the others as a ground, now these others as advancing 
out of the first as a background. The difficulty of 
selecting either interpretation at will becomes greater, 
of course, in those cases where there is a powerful sug- 
gestion of some particular local arrangement, as, for 
example, the case of patterns much brighter than the 
ground, and especially of such as represent known 
objects, as flowers. Yet even here a strong effort of 
imagination will often suffice to bring about a conver- 
sion of the first appearance. 

A somewhat similar choice of interpretation offers 
itself in looking at elaborate decorative patterns. 
When we strongly imagine any number of details to be 
elements of one figure, they seem to become so ; and a 
given detail positively appears to alter in character 
according as it is viewed as an element of a more or 
less complex figure. 

1 When the drawing, by its adherence to the laws of perspective, 
does not powerfully determine the eye to see it in one way rather than 
in the other (as in Figs. 5 to 7), the disposition to see the one form 
rather than the other points to differences in the frequency of the 
original forms in our daily experience. At the same time, it is to be 
observed that, after looking at the drawing for a time under each 
aspect, the suggestion now of the one and now of the other forces itself 
on the mind in a curious and unaccountable way. 



FANCIFUL INTEEPEETATION. 99 

These examples show what force belongs to a vivid 
preconception, if this happens to fit only very roughly 
the impression of the moment, that is to say, if the 
interpretative image is one of the possible suggestions 
of the impression. The play of imagination takes a 
wider range in those cases where the impression is very 
indefinite in character, easily allowing of a considerable 
variety of imaginative interpretation. 

I referred at the beginning of this account of sense- 
illusions to the readiness with which the mind deceives 
itself with respect to the nature and causes of the vague 
sensations which usually form the dim background of 
our mental life. A person of lively imagination, by 
trying to view these in a particular way, and by selec- 
tively attending to those aspects of the sensation which 
answer to the caprice of the moment, may give a 
variety of interpretations to one and the same set of 
sensations. For example, it is very easy to get con- 
fused with respect to those tactual and motor feelings 
which inform us of the position of our bodily members. 
And so, when lying in bed, and attending to the sen- 
sations connected with the legs, we may easily delude 
ourselves into supposing that these members are 
arranged in a most eccentric fashion. Similarly, by 
giving special heed to the sensations arising in connec- 
tion with the condition of the skin at any part, we may 
amuse ourselves with the strangest fancies as to what 
is going on in these regions. 

Again, when any object of visual perception is 
indistinct or indefinite in form, there is plainly an 
opening for this capricious play of fancy in transform- 
ing the actual. This is illustrated in the well-known 



100 ILLUSIONS OF PERCEPTION, 

pastime of discovering familiar forms, such as those 
of the human head and animals, in distant rocks and 
clouds, and of seeing pictures in the fire, and so on. 
The indistinct and indefinite shapes of the masses of 
rock, cloud, or glowing coal, offer an excellent fL-ld for 
creative fancy, and a person of lively imagination will 
discover endless forms in what, to an unimaginative 
eye,«is a formless waste. Johannes Muller relates that, 
when a child, he used to spend hours in discovering 
the outlines of forms in the partly blackened and 
cracked stucco of the house that stood opposite to his 
own. 1 Here it is plain that, while experience and 
association are not wholly absent, but place certain 
wide limits on this process of castle-building, the spon- 
taneous activity of the percipient mind is the great 
determining force. 

So much as to the influence of a perfectly unfet- 
tered voluntary attention on the determination of the 
stage of preperception, and, through this, of the result- 
ing interpretation. Let us now pass to cases in which 
this direction of preperception follows not the caprice of 
the moment, but the leading of some fixed predisposi- 
tion in the interpreter's mind. In these cases attention 
is no longer free, but fettered, only it is now fettered 
rather from within thau from without ; that is to say, 
The dominating preperception is much more the result 
of an independent bent of the imagination than of some 
suggestion forced on the mind by the actual impression 
of the moment. 

1 TJeber die pliantastischen Geslchtserscheinungen, p. 45. 






VISION AND BENT OF IMAGINATION. 101 

Involuntary Mental I ^readjustment. 

If we glance back at the examples of capricious 
selection just noticed, we shall see that they are 
really limited not only by the character of the im- 
pression of the time, but also by the mental habits 
of the spectator. That is to say, we find that his 
fancy runs in certain definite directions, and takes 
certain habitual forms. It has already been observed 
that the percipient mind has very different attitudes 
with respect to various kinds of impression. Towards 
some it holds itself at a distance, while towards others, 
it at once bears itself familiarly ; the former are such 
as answer to its previous habit and bent of imagination, 
the latter such as do not so answer. 

This bent of the interpretative imagination assumes, 
as we have already seen, two forms, that of a compara- 
tively permanent disposition, and that of a temporary 
state of expectation or mental preparedness. Illusion 
may arise in connection with either of these forms. 
Let us illustrate both varieties, beginning with those 
which are due to a lasting mental disposition. 

It is impossible here to specify all the causes of 
illusion residing in organized tendencies of the mind. 
The whole past mental life, with its particular shade 
of experience, its ruling emotions, and its habitual 
direction of fancy, serves to give a particular colour 
to new impressions, and so to favour illusion. There 
is a " personal equation " in perception as in belief — 
an amount of erroneous deviation from the common 
average view of external things, which is the outcome 
of individual temperament and habits of mind. Thus, 



102 ILLUSIONS OF PERCEPTION. 

a naturally timid man will be in general disposed to 
see ugly and fearful objects where a perfectly un- 
biased mind perceives nothing of the kind ; and the 
forms which these objects of dread will assume are de- 
termined by the character of his past experience, and 
by the customary direction of his imagination. 

In perfectly healthy states of mind this influenco 
of temperament and mental habit on the perception 
of external objects is, of course, very limited ; it shows 
itself more distinctly, as we shall see, in modifying 
the estimate of things in relation to the sesthetic and 
other feelings. This applies to the mythical poetical 
way of looking at nature — a part of our subject to 
which we shall have to return later on. 

Passing now from the effect of such permanent 
dispositions, let us look at the more striking results 
of temporary expectancy of mind. 

When touching on the influence of such a tempo- 
rary mental attitude in the process of correct per- 
ception, I remarked that this readiness of mind might 
assume an indefinite or a definite form. We will 
examine the effect of each kind in the production of 
illusion. 

Action of Sub-Expectation. 

First of all, then, our minds may at the particular 
moment be disposed to entertain any one of a vaguely 
circumscribed group of images. Thus, to return to 
the example already referred to, when in Italy, we are 
in a state of readiness to frame any of the images 
that we have learnt to associate with this country. 
We may not be distinctly anticipating any one kind 






TEMPOEAEY BENT OF IMAGINATION. 103 

of object, but are nevertheless in a condition of sub- 
expectation with reference to a large number of objects. 
Accordingly, when an impression occurs which answers 
only very roughly to one of the associated images, 
there is a tendency to superimpose the image on the 
impression. In this way illusion arises. Thus, a man, 
when strolling in a cathedral, will be apt to take any 
kind of faint hollow sound for the soft tones of an 
organ. 

The disposition to anticipate fact and reality in this 
way will be all the stronger if, as usually happens, 
the mental images thus lying ready for use have an. 
emotional colouring. Emotion is the great disturber 
of all intellectual operations. It effects marvellous 
things, as we shall presently see, in the region of 
illusory belief, and its influence is very marked in the 
seemingly cooler region of external perception. The 
effect of any emotional excitement appears to be to 
give a preternatural vividness and persistence to the 
ideas answering to it, that is to say, the ideas which are 
its excitants, or which are otherwise associated with 
it. Owing to this circumstance, when the mind is 
under the temporary sway of any feeling, as, for ex- 
ample, fear, there will be a special readiness to interpret 
objects by help of images congruent with the emotion. 
Thus, a man under the control of fear will be ready 
to see any kind of fear-inspiring object whenever there 
is any resemblance to such in the things actually 
present to his vision. The state of awe which the sur- 
rounding circumstances of a spiritualist seance inspires 
produces a general readiness of mind to perceive what 
is strange, mysterious, and apparently miraculous. 



101 ILLUSIONS OF PERCEPTION. 

It is worth noting, perhaps, that those delightful 
half-illusions which imitative art seeks to produce are 
greatly favoured by such a temporary attitude of the 
interpreting imagination. In the theatre, for example, 
we are prepared for realizing the semblance of life 
that is to be unfolded before us. We come knowing 
that what is to be performed aims at representing a 
real action or actual series of events. We not impro- 
bably work ourselves into a slightly excited state in 
anticipation of such a representation. More than this, 
as the play progresses, the realization of what has 
gone before produces a strong disposition to believe in 
the reality of what is to follow. And this effect is pro- 
portionate to the degree of coherence and continuity 
in the action. In this way, there is a cumulative 
effect on the mind. If the action is good, the illusion, 
as every play-goer knows, is most complete towards 
the end. 

Were it not for all this mental preparation, the illu- 
sory character of the performance would be too patent 
to view, and our enjoyment would suffer. A man is 
often aware of this when coming into a theatre during 
the progress of a piece before his mind accommodates 
itself to the meaning of the play. And the same 
thing is recognizable in the fact that the frequenter 
of the theatre has his susceptibility to histrionic 
delusion increased by acquiring a habit of looking out 
tor the meaning of the performance. Persons who 
first see a play, unless they be of exceptional imagina- 
tion and have thought much about the theatre — as 
Charlotte Bronte, for instance — hardly feel the illusion 
at all. At least, this is true of the opera, where the 



PREADJUSTMENT IN AST ILLUSION. 105 

departure from reality is so striking that the im- 
pression can hardly fail to be a ludicrous one, till the 
habit of taking the performance for what it is intended 
to be is fully formed. 1 

A similar effect of intellectual preadjustment is 
observable in the fainter degrees of illusion produced 
by pictorial art. Here the undeceiving circumstances, 
the flat surface, the surroundings, and so on, would 
sometimes be quite sufficient to prevent the least 
degree of illusion, were it not that the spectator comes 
prepared to see a representation of some real object. 
This is our state of mind when we enter a picture 
gallery or approach what we recognize as a picture 
on the wall of a room. A savage would not " realize " 
a slight sketch as soon as one accustomed to pictorial 
representation, and ready to perform the required in- 
terpretative act. 2 

So much as to the effect of an indefinite state of 
sub-expectation in misleading our perceptions. Let 
us now glance at the results of definite preimagination, 
including what are generally known as expectations. 

1 Another side of histrionic illusion, the reading of the imitated 
feelings into the actors' minds, will be dealt with in a later chapter. 

2 In a finished painting of any size this preparation is hardly 
necessary. In these cases, in spite of the great deviations from truth 
in pictorial representation already touched on, the amount of essential 
agreement is so large and so powerful in its effect that even an 
intelligent animal will experience an illusion. Mr. Romanes sends 
me an interesting account of a dog, that had never been accustomed 
to pictures, having been put into a state of great excitement by the 
introduction of a portrait into a room, on a level with his eye. It is 
not at all improbable that the lower animals, even when sane, are fre- 
quently the subjects of slight illusion. That animals dream is a fact 
which is observed as long ago as the age of Lucretius 

6 



106 ILLUSIONS OF PERCEPTION. 

Effects of Vivid Expectation. 

Such expectations may grow out of some present 
objective facts, which serve as signs of the expected 
event ; or they may arise by way of verbal suggestion ; 
or, finally, they may be due to internal spontaneous 
imagination. 

In the first place, then, the expectations may grow 
out of previous perceptions, while, nevertheless, the 
direction of the expectation may be a wrong one. 
Here the interpreting imagination is, in a large sense, 
under the control of external suggestion, though, with 
respect to the particular impression that is miscon- 
strued, it may be regarded as acting independently 
and spontaneously. 

Illustrations of this effect in producing illusion 
will easily occur to the reader. If I happen to have 
heard that a particular person has been a soldier 
or clergyman, I tend to see the marks of the class 
in this person, and sometimes find that this process 
of recognition is altogether illusory. Again, let us 
suppose that a person is expecting a friend by a 
particular train. A passenger steps out of the train 
bearing a superficial resemblance to his friend ; in 
consequence of which he falls into the error of false 
identification. 

The delusions of the conjuror depend on a similar 
principle. The performer tells his audience that he is 
about to do a certain thing, for example, take a number 
of animals out of a small box which is incapable of 
holding them. The hearers, intent on what has been 
said, vividly represent to themselves the action de- 



DELUSIONS OF THE CONJUEOE. 107 

scribed. And in this way their attention becomes 
bribed, so to speak, beforehand, and fails to notice the 
inconspicuous movements which would at once clear 
up the mystery. Similarly with respect to the illusions 
which overtake people at spiritualist seances. The in- 
tensity of the expectation of a particular kind of object 
excludes calm attention to what really happens, and 
the slightest impressions which answer to signs of the 
object anticipated are instantly seized by the mind and 
worked up into illusory perceptions. 

It is to be noted that even when the impression 
cannot be made to tally exactly with the expectation, 
the force of the latter often effects a grotesque con- 
fusion of the perception. If, for example, a man goes 
into a familiar room in the dark in order to fetch 
something, and for a moment forgets the particular 
door by which he has entered, his definite expectation 
of finding things in a certain order may blend with the 
order of impressions experienced, producing for the 
moment a most comical illusion as to the actual state 
of things. 

When the degree of expectation is unusually great, 
it may suffice to produce something like the counterfeit 
of a real sensation. This happens when the present 
circumstances are powerfully suggestive of an im- 
mediate event. The effect is all the more powerful, 
moreover, in those cases where the object or event 
expected is interesting or exciting, since here the 
mental image gains in vividness through the emotional 
excitement attending it. Thus, if I am watching a 
train off and know from all the signs that it is just 
about to start, I easily delude myself into the con- 



108 ILLUSIONS OF PEKCEPTION. 

viction that it has begun to start, when it is really 
still. 1 An intense degree of expectation may, in such 
cases, produce something indistinguishable from an 
actual sensation. This effect is seen in such common 
experiences as that the sight of food makes the mouth 
of a hungry man water; that the appearance of a 
surgical instrument produces a nascent sensation of 
pain ; and that a threatening movement, giving a 
vivid anticipation of tickling, begets a feeling which 
closely approximates to the result of actual tickling. 

One or two very striking instances of such imagined 
sensations are given by Dr. Carpenter. 2 Here is one. 
An officer who superintended the exhuming of a coffin 
rendered necessary through a suspicion of crime, 
declared that he already experienced the odour of 
decomposition, though it was afterwards found that 
the coffin was empty. 3 

It is, of course, often difficult to say, in such cases 
as these, how far elements of actual sensation co-operate 
in the production of the illusions. Thus, in the case 
just mentioned, the odour of the earth may have been 
the starting-point in the illusion. In many cases, how- 
ever, an imaginative mind appears to be capable of 

1 This kind of illusion is probably facilitated by the fact that the 
eye is often performing slight movements without any clear conscious- 
ness of them. See what was said about the limits of sensibility, p. 50. 

8 Mental Physiology, fourth edit., p. 158. 

3 In persons of very lively imagination the mere representation of 
an object or event may suffice to bring about such a semblance o'f 
sensation. Thus, M. Taine (op. cit., vol. i. p. 94) vouches for the 
assertion that "one of the most exact and lucid of modern novelists," 
when working out in his imagination the poisoning of one of his 
fictitious characters, had so vivid a gustatory sensation of arsenic that 
he was attacked by a violent fit of indigestion. 



GROSSER ACTIVE ILLUSIONS. 109 

transforming a vivid expectation into a nascent stage 
of sensation. Thus, a mother thinking of her sick 
child in an adjoining room, and keenly on the alert 
for its voice, will now and again fancy she really 
hears it when others hear nothing at all. 



Transition to Hallucination. 

It is plain that in these cases illusion approaches 
to hallucination. Imagination, instead of waiting on 
sensation, usurps its place and imitates its appearance. 
Such a " subjective " sensation produced by a powerful 
expectation might, perhaps, by a stretch of language, 
be regarded as an illusion, in the narrow sense, in so 
far as it depends on the suggestive force of a com- 
plete set of external circumstances; on the other 
hand, it is clearly an hallucination in so far as it is the 
production of the semblance of an external impres- 
sion without any external agency corresponding to 
this. 

In the class of illusory expectations just considered 
the immediately present environment still plays a part, 
though a much less direct part than that observable 
in the first large group of illusions. We will now pass 
to a second mode of illusory expectation, where 
imagination is still more detached from the present 
surroundings. 

A common instance of this kind of expectation is 
the so-called " intuition," or presentiment, that some- 
thing is going to happen, which expectation has no 
basis in fact. It does not matter whether the expecta- 
tion has arisen by way of another's words or by way 



110 ILLUSIONS OP PERCEPTION. 

of personal inclinations. A strong wish, for a thing 
will, in an exalted state of mind, beget a vivid 
anticipation of it. This subject will be touched on 
again under the Illusions of Belief. Here I am con- 
cerned to point out that such presentiments are fertile 
sources of sense-illusion. The history of Church 
miracles, visions, and the like amply illustrates the 
effect of a vivid anticipation in falsifying the percep- 
tions of external things. 

In persons of a lively imagination any recent 
occupation of the mind with a certain kind of mental 
image may suffice to beget something equivalent to a 
powerful mode of expectation. For example, we are 
told by Dr. Tuke that on one occasion a lady, whose 
imagination had been dwelling on the subject of 
drinking fountains, "thought she saw in a road a newly 
erected fountain, and even distinguished an inscription 
upon it, namely, ' If any man thirst, let him come 
unto Me, and drink.' She afterwards found that what 
she had actually seen was only a few scattered stones." 1 
In many cases there seems to be a temporary preter- 
natural activity of the imagination in certain directions, 
of which no very obvious explanation is discoverable. 
Thus, we sometimes find our minds dwelling on some 
absent friend, without being able to give any reason 
for this mental preoccupation. And in this way arise 
strong temporary leanings to illusory perception. It 
may be said, indeed, that all unwonted activity of the 
imagination, however it arises, has as its immediate 
result a temporary mode of expectation, definite or 

1 Mentioned by Dr. Carpenter (Mental Physiology, p. 207), where 
other suiious examples are to be found. 



ACTIVE ILLUSION AND HALLUCINATION. Ill 

indefinite, which easily confuses our perceptions of 
external things. 

In proportion as this pre-existing imaginative 
impulse becomes more powerful, the amount of actual 
impression necessary to transform the mental image 
into an illusory perception becomes less ; and, what is 
more important, this transformation of the internal 
image involves a larger and larger displacement of the 
actual impression of the moment. A man whose mind 
is at the time strongly possessed by one kind of image, 
will tend to project this outwards with hardly any 
regard to the actual external circumstances. 

This state of things is most completely illustrated 
in many of the grosser illusions of the insane. Thus, 
when a patient takes any small objects, as pebbles, for 
gold and silver, under the influence of the dominant 
idea of being a millionaire, it is obvious that external 
suggestion has very little to do with the self-deception. 
The confusions into which the patient often falls with 
respect to the persons before him show the same state 
of mind ; for in many cases there is no discoverable 
individual resemblance between the person actually 
present and the person for whom he is taken. 

It is evident that when illusion reaches this stage, 
it is scarcely distinguishable from what is specially 
known as hallucination. As I have remarked in 
setting out, illusion and hallucination shade one into 
the other much too gradually for us to draw any sharp 
line of demarcation between them. And here we see 
that hallucination differs from illusion only in the pro- 
portion in which the causes are present. When the 
internal imaginative impulse reaches a certain strength, 



112 ILLUSIONS OF PEECEPTION. 

it becomes self-sufficient, or independent of any ex- 
ternal impression. 

This intimate relation between the extreme form 
of active illusion and hallucination may be seen, too, 
by examining the physical conditions of each. As I 
have already remarked, active illusion has for its 
physiological basis a state of sub-excitation, or an 
exceptional condition of irritability in the structures 
engaged in the act of interpretative imagination. The 
greater the degree of this irritability, the less will be 
the force of external stimulation needed to produce 
the effect of excitation, and the more energetic will 
be the degree of this excitation. Moreover, it is plain 
that this increase in the strength of the excitation 
will involve an extension of the area of excitation 
till, by-and-by, the peripheral regions of the nervous 
system may be involved just as in the case of external 
stimulation. This accounts for the gradual displace- 
ment of the impression of the moment by the mental 
image. It follows that when the irritability reaches 
a certain degree, the amount of external stimulus 
needed may become a vanishing quantity, or the state 
of sub-excitation may of itself develop into one of 
full activity. 

Hallucinations. 

I do not propose to go very fully into the de- 
scription and explanation of hallucinations here, since 
they fall to a large extent under the category of 
distinctly pathological phenomena. Yet our study of 
illusions would not be complete without a glance at 
this part of the subject. 



RUDIMENTARY HALLUCINATIONS. 113 

Hallucination, by which I mean the projection of 
a mental image outwards when there is no external 
agency answering to it, assumes one of two fairly 
distinct forms : it may present itself either as a sem- 
blance of an external impression with the minimum 
amount of interpretation, or as a counterfeit of a 
completely developed percept. Thus, a visual hallu- 
cination may assume the aspect of a sensation of 
light or colour which we vaguely refer to a certain 
region of the external world, or of a vision of some 
recognizable object. All of us frequently have in- 
complete visual and auditory hallucinations of the 
first order, whereas the complete hallucinations of 
the second order are comparatively rare. The first 
I shall call rudimentary, the second developed, hallu- 
cinations. 

Rudimentary hallucinations may have either a 
peripheral or a central origin. They may first of all 
have their starting-point in those subjective sensations 
which, as we have seen, are connected with certain 
processes set up in the peripheral regions of the ner- 
vous system. Or, secondly, they may originate in a 
certain preternatural activity of the sensory centres, or 
"sensorium," in what has been called by German 
physiologists an automatic excitation of the central 
structures, which activity may probably diffuse itself 
downwards to the peripheral regions of the nerves. 
Baillarger would call hallucinations of the former 
class " psycho-sensorial," those of the latter class 
purely " psychical," hallucinations. 1 

1 See Anncdes Medico Fsychologiques, torn. vi. p. 168, etc. ; torn. vii. 
p. 1, etc. 



114 ILLUSIONS OF PEECEPTION. 

It is often a matter of great difficulty to determine 
which, part of the nervous system is originally concerned 
in these rudimentary hallucinations. It is probable 
that in normal life they are most frequently due to 
peripheral disturbance. And ii seems reasonable to 
suppose that where the hallucination remains in this 
initial stage of a very incompletely interpreted visual 
or auditory impression, whether in normal or abnormal 
life, its real physiological source is the periphery. 
For the automatic excitation of the centres would 
pretty certainly issue in the semblance of some definite, 
familiar variety of sense-impression which, moreover, 
as a part of a complex state known as a percept, would 
instantly present itself as a completely formed quasi- 
percept. In truth, we may pretty safely argue that if 
it is the centre which is directly thrown into a state 
of activity, it will be thrown into the usual complex, 
that is to say, perceptional, mode of activity. 

Let us now turn to hallucinations properly so 
called, that is to say, completely developed quasi-per- 
cepts. These commonly assume the form of visual or 
auditory hallucinations. Like the incomplete halluci- 
nations, they may have their starting-point either in 
some disturbance in the peripheral regions of the 
nervous system or in the automatic activity of the 
central structures : or, to use the language of Baillarger, 
we may say that they are either "psycho-sensorial" or 
purely "psychical." A subjective visual sensation, 
arising from certain conditions in the retina and con- 
nected portions of the optic nerve, may by chance 
resemble a familiar impression, and so be at once 
interpreted as an effect of a particular external object. 



DEVELOPED HALLUCINATIONS. 115 

More frequently, however, the automatic activity of the 
centres must be regarded, either in part or altogether, 
as the physiological cause of the phenomenon. This 
is clearly the case when, on the subjective side, the 
hallucination answers to a preceding energetic activity 
of the imagination, as in the case of the visionary and 
the monomaniac. Sometimes, however, as we have seen, 
the hallucinatory percept answers to previous pro- 
longed acts of perception, leaving a kind of reverbera- 
tion in the structures concerned; and in this case it is 
obviously impossible to say whether the peripheral or 
central regions (if either) have most to do with the 
hallucination. 1 

The classifications of the causes of hallucination to 
be met with in the works of pathologists, bear out the 
distinction just drawn. Griesinger tells us [op. cit., 
pp. 94, 95) that the general causes of hallucination 
are : (1) Local disease of the organ of sense ; (2) a state 
of deep exhaustion either of mind or of body ; (3) 
morbid emotional states, such as fear ; (4) outward calm 
and stillness between sleeping and waking ; and (5) the 
action of certain poisons, as haschisch, opium, bella- 
donna. The first cause points pretty distinctly to a 
peripheral origin, whereas the others appear to refer 
mainly, if not exclusively, to central derangements. 

1 I have already touched on the resonance of a sense-impression 
when the stimulus has ceased to act (see p. 55). The remarks in the 
text hold good of all such after-impressions, in so far as they take the 
form of fully developed percepts. A good example is the recurrence 
of the images of microscopic preparations, to which the anatomist is 
liable. (See Lewes, Problems of Life and Mind, third series, vol. ii. p. 
299.) Since a complete hallucination is supposed to involve the peri- 
pheral regions of the nerve, the mere fact of shutting the eye would 
not, it is clear, serve as a test of the origin of the illusion. 



116 ILLUSIONS OF PEKCEPTION. 

Excessive fatigue appears to predispose the central 
structures to an abnormal kind of activity, and the same 
effect may be brought about by emotional agitation and 
by the action of poisons. The fourth case mentioned 
here, absence of external stimulation, would naturally 
raise the nervous structures to an exceptional pitch of 
excitability. Such a condition would, moreover, prove 
favourable to hallucination by blurring the distinction 
between mental image and actual impression. 

Hallucinations of Normal Life. 

In normal life, perfect hallucinations, in the strict 
sense as distinct from illusions, are comparatively rare. 
Fully developed persistent hallucinations, as those of 

Nicolai, the Berlin bookseller, and of Mrs. A , the 

lady cited by Sir D. Brewster, in his Letters on Natural 
Magic, point to the presence of incipient nervous 
disorder. In healthy life, on the other hand, while 
everybody is familiar with subjective sensations such as 
flying spots, phosphenes, ringing in the ears, few fall 
into the error of seeing or hearing distinct recognizable 
objects in the absence of all external impressions. In 
the lives of eminent men we read of such phenomena as 
very occasional events. Malebranche, for example, is 
said to have heard the voice of God calling him. 
Descartes says that, after a long confinement, he was 
followed by an invisible person, calling him to pursue 
his search for truth. Dr. Johnson narrates that he 
once heard his absent mother calling him. Byron tells 
us that he was sometimes visited by spectres. Goethe 
records that he once saw an exact counterpart of him- 



HALLUCINATION IN SANITY. 117 

self coming towards him. Sir Walter Scott is said to 
have seen a phantom of the dead Byron. It is possible 
that all of us are liable to momentary hallucinations at 
times of exceptional nervous exhaustion, though they 
are too fugitive to excite our attention. 

When not brought on by exhaustion or artificial 
means, the hallucinations of the sane have their origin 
in a preternatural power of imagination. It is well 
known that this power can be greatly improved by 
attention and cultivation. Goethe used to exercise him- 
self in watching for ocular spectra, and could at will 
transform these subjective sensations into definite forms, 
such as flowers ; and Johannes Muller found he had the 
same power. 1 Stories are told of portrait painters who 
could summon visual images of their sitters with a 
vividness equal to that of reality, and serving all the 
purposes of their art. Mr. Galton's interesting inquiries 
into the power of " visualizing " would appear to prove 
that many people can at will sport on the confines of 
the phantom world of hallucination. There is good 
reason to think that imaginative children tend to con- 
fuse mental images and percepts. 2 

1 That subjective sensation may become the starting-point in 
complete hallucination is shown in a curious instance given by 
Lazarus, and quoted by Tame, op. cit., vol. i. p. 122, st seq. The 
German psychologist relates that, on one occasion in Switzerland, after 
gazing for some time on a chain of snow-peaks, he saw an apparition of 
an absent friend, looking like a corpse. He goes on to explain that 
this phantom was the product of an image of recollection which some- 
how managed to combine itself with the (positive) after-image left by 
the impression of the snow-surface. 

2 For an account of Mr. Galton's researches, see Mind, No. xix. 
Compare, however, Professor Bain's judicious observations on these 



118 ILLUSIONS OF PERCEPTION. 

Tlie Hallucinations of Insanity. 

The hallucinations of the insane are but a fuller 
manifestation of forces that we see at work in normal 
life. Their characteristic is that they simulate the form 
of distinctly present objects, the existence of which is 
not instantly contradicted by the actual surroundings 
of the moment. 1 The hallucinations have their origin 
partly in subjective sensations, which are probably 
connected with peripheral disturbances, partly and 
principally in central derangements. 2 These include 
profound emotional changes, which affect the ruling 
mental tone, and exert a powerful influence on the 
course of the mental images. The hallucinations of 
insanity are due to a projection of mental images 
which have, owing to certain circumstances, gained a 
preternatural persistence and vividness. Sometimes it 
is the images that have been dwelt on with passionate 
longing before the disease, sometimes those which have 
grown most habitual through the mode of daily occupa- 

results in the next number of Mind. The liability of children to take 
images for percepts, is illustrated by the experiences related in a 
curious little work, Visions, by E. H. Clarke, M.D. (Boston, U.S., 
1878), pp. 17, 46, and 212. 

1 A common way of describing the relation of the hallucinatory to 
real objects, is to say that the former appear partly to cover and hide 
the latter. 

8 Griesingcr remarks that the forms of the hallucinations of the 
insane rarely depend on sense-disturbances alone. Though these are 
often the starting-point, it is the whole mental complexion of the 
time which gives the direction to the imagination. The common 
experience of seeing rats and mice running about during a fit of 
delirium tremens very well illustrates the co-operation of peripheral 
impressions not usually attended to, and possibly magnified by the 
morbid state of sensibility of the time (in this case flying spots, muscse 
volitantes), with emotional conditions. (See Gricsinger, loc. tit., p. 96.) 



HALLUCINATION IN INSANITY. 119 

tion, 1 and sometimes those connected with some 
incident at or near the time of the commencement of 
the disease. 

In mental disease, auditory hallucinations play a 
part no less conspicuous than visual. 2 Patients fre- 
quently complain of having their thoughts spoken to 
them, and it is not uncommon for them to imagine 
that they are addressed by a number of voices at the 
same time. 3 

These auditory hallucinations offer a good oppor- 
tunity for studying the gradual growth of centrally 
originating hallucinations. In the early stages of the 
disease, the patient partly distinguishes his represen- 
tative from his presentative sounds. Thus, he talks of 
sermons being composed to him in his head. He calls 
these " internal voices," or " voices of the soul." It 

1 TTundt (Physidlogische Psychologie, p. 652) tells us of an insane 
woodman who saw logs of wood on all hands in front of the real objects. 

2 It is stated by Baillarger (Memoires de V Academic Royale de 
Medicine, torn. xii. p. 273, etc.) that while visual hallucinations are 
more frequent than auditory in healthy life, the reverse relation holds 
in disease. At the same time, Griesinger remarks (loc. cit., p. 98) 
that visual hallucinations are rather more common than auditory in 
disease also. This is what we should expect from the number of 
subjective sensations connected with the peripheral organ of vision. 
The greater relative frequency of auditory hallucinations in disease, 
if made out, would seem to depend on the close connection between 
articulate sounds and the higher centres of intelligence, which centres 
are naturally the first to be thrown out of working order. It is 
possible, moreover, that auditory hallucinations are quite as common 
as visual in states of comparative health, though more easily over- 
looked. Professor Huxley relates that he is liable to auditory though 
not to visual hallucinations. (See Elementary Lessons in Physiology, 
p. 267.) 

3 See Baillarger, Memoires de VAcadtinie Royale de Medicine, torn. 
xii. p. 273, et se%. 



120 ILLUSIONS OF PEECEPTION. 

is only when the disease gains ground and the central 
irritability increases that these audible thoughts become 
distinctly projected as external sounds into more or 
less definite regions of the environment. And it is 
exceedingly curious to notice the different directions 
which patients give to these sounds, referring them 
now to a quarter above the head, now to a region below 
the floor, and so on. 1 

Bange of Sense-Illusions. 

And now let us glance back to see the path we 
have traversed. We set out with an account of per- 
fectly normal perception, and found, even here, in the 
projection of our sensations of colour, sound, etc., into 
the environment or to the extremities of the organism, 
something which, from the point of view of physical 
science, easily wears the appearance of an ingredient 
of illusion. 

Waiving this, however, and taking the word illusion 
as commonly understood, we find that it begins when 
the element of imagination no longer answers to a 
present reality or external fact in any sense of this ex- 
pression. In its lowest stages illusion closely counter- 
feits correct perception in the balance of the direct 
factor, sensation, and the indirect factor, mental repro- 
duction or imagination. The degree of illusion in- 
creases in proportion as the imaginative element gains 

1 See Baillarger, Aimales Medico-Psycliologiques, torn. vi. p. 168 
et . seq. ; also torn. xii. p. 273, et seq. Compare Griesinger, op. cit. In a 
curious work entitled Du Demon de Soerate (Paris, 1856), M. Lelut 
seeks to prove that the philosopher's admonitory voice was an inci« 
pient auditory hallucination symptomic of a nascent stage of mental 
alienation. 



SCALE OF SENSE-ILLUSION. 121 

in force relatively to the present impression ; till, in 
the wild illusions of the insane, the amount of actual 
impression becomes evanescent. When this point is 
reached, the act of imagination shows itself as a purely 
creative process, or an hallucination. 

While we may thus trace the progress of illusion 
towards hallucination by means of the gradual increase 
in force and extent of the imaginative, or indirect, as 
opposed to the sensuous, or direct, element in percep- 
tion, we have found a second starting-point for this 
movement in the mechanism of sensation, involving, as 
it does, the occasional production of "subjective sen- 
sations." Such sensations constitute a border-land 
between the regions of illusion in the narrow sense, 
and hallucination. In their simplest and least de- 
veloped form they may be regarded, at least in the 
case of hearing and sight, as partly hallucinatory ; and 
they serve as a natural basis for the construction of 
complete hallucinations, or hallucinatory percepts. 

In these different ways, then, the slight, scarcely 
noticeable illusions of normal life lead up to the most 
startling hallucinations of abnormal life. From the 
two poles of the higher centres of attention and 
imagination on the one side, and the lower regions of 
nervous action involved in sensation on the other side, 
issue forces which may, under certain circumstances, 
develop into full hallucinatory percepts. Thus closely 
is healthy attached to morbid mental life. There 
seems to be no sudden break between our most sober 
e very-day recognitions of familiar objects and the 
wildest hallucinations of the demented. As we pass 
from the former to the latter, we find that there is 



122 ILLUSIONS OF PERCEPTION. 

never any abrupt transition, never any addition of per- 
fectly new elements, but only that the old elements 
go on combining in ever new proportions. 

The connection between the illusory side of our life 
and insanity may be seen in another way. All illusion 
has as its negative condition an interruption of the 
higher intellectual processes, the due control of our 
mental representations by reflection $nd reason. In 
the case of passive illusions, the error arises from our 
inability to subordinate the suggestion made by some 
feature of the present impression to the result of a 
fuller inspection of the object before us, or of a wider 
reflection on the past. In other words, our minds are 
dominated by the partial and the particular, to the 
exclusion of the total or the general. In active 
illusions, again, the powers of judgment and reflection, 
including those of calm perception itself, temporarily 
vacate their throne in favour of imagination. And 
this same suspension of the higher intellectual 
functions, the stupefaction of judgment and reflection 
made more complete and permanent, is just what 
characterizes insanity. 

We may, perhaps, express this point of connection 
between the illusions of normal life and insanity by 
help of a physiological hypothesis. If the nervous 
system has been slowly built up, during the course of 
human history, into its present complex form, it follows 
that those nervous structures and connections which 
have to do with the higher intellectual processes, or 
which represent the larger and more general relations 
of our experience, have been most recently evolved. 
Consequently, they would be the least deeply organized, 



CONTINUITY OP SANE AND INSANE LIFE. 123 

and so the least stable ; that is to say, the most liable 
to be thrown Jwrs de combat. This is what happens 
temporarily in the case of the sane, when the mind is 
held fast by an illusion. And, in states of insanity, we 
see the process of nervous dissolution beginning with 
these same nervous structures, and so taking the 
reverse order of the process of evolution. 1 And thus, 
we may say that throughout the mental life of the 
most sane of us, these higher and more delicately 
balanced structures are constantly in danger of being 
reduced to that state of inefficiency, which in its full 
manifestation is mental disease. 

Does this way of putting the subject seem alarm- 
ing ? Is it an appalling thought that our normal 
mental life is thus intimately related to insanity, and 
graduates away into it by such fine transitions ? A 
moment's reflection will show that the case is not so 
bad as it seems. It is well to remind ourselves that 
the brain is a delicately adjusted organ, which very 
easily gets disturbed, and that the best of us are liable 
to become the victims of absurd illusion if we habitu- 
ally allow our imaginations to be overheated, whether 
by furious passion or by excessive indulgence in the 
pleasures of day-dreaming, or in the intoxicating mys- 
teries of spiritualist seances. But if we take care to 
keep our heads cool and avoid unhealthy degrees of 
mental excitement, we need not be very anxious on the 
ground of our liability to this kind of error. As I have 
tried to show, our most frequent illusions are necessarily 
connected with something exceptional, either in the 

1 This is well brought out by Dr. J. Hughlings Jackson, in the 
papers in Brain, already referred to. 



124 ILLUSIONS OF PERCEPTION. 

organism or in the environment. That is to say, it 
is of the nature of illusion in healthy conditions of 
body and mind to be something very occasional and 
relatively unimportant. Our perceptions may be re- 
garded as the reaction of the mind on the impressions 
borne in from the external world, or as a process of 
adjustment of internal mental relations to external 
physical relations. If this process is, in the main, a 
right one, we need not greatly trouble, because it is 
not invariably so. We should accept the occasional 
failure of the intellectual mechanism as an inseparable 
accompaniment of its general efficiency. 
, To this it must be added that many of the illusions 
described above can hardly be called cases of non- 
adaptation at all, since they have no relation to the 
practical needs of life, and consequently are, in a 
general way, unattended to. In other cases, again, 
namely, where the precise nature of a present sen- 
sation, being practically an unimportant matter, is 
usually unattended to, as in the instantaneous recog- 
nition of objects by the eye under changes of illumi- 
nation, etc., the illusion is rather a part of the process 
of adaptation, since it is much more important to 
recognize the permanent object signified by the sen- 
sation than the precise nature of the present sensational 
" sign " itself. 

Finally, it should never be forgotten that in nor- 
mal states of mind there is always the possibility of 
rectifying an illusion. What distinguishes abnormal 
from normal mental life is the persistent occupation of 
the mind by certain ideas, so that there is no room for 
the salutary corrective effect of reflection on the actual 



SANE LIFE MASKED OFF FROM INSANE. 125 

impression of the moment, by which we are wont to 
" orientate," or take our bearings as to the position of 
things about us. In sleep, and in certain artificially 
produced states, much the same thing presents itself. 
Images become realities just because they are not 
instantly recognized as such by a reference to the 
actual surroundings of the moment. But in normal 
waking life this power of correction remains with us. 
We may not exercise it, it is true, and thus the illusion 
will tend to become more or less persistent and recur- 
ring ; for the same law applies to true and to false per- 
ception : repetition makes the process easier. But if 
we only choose to exert ourselves, we can always keep 
our illusions in a nascent or imperfectly developed 
stage. This applies not only to those half-illusions 
into which we voluntarily fall, but also to the more 
irresistible passive illusions, and those arising from an 
over-excited imagination. Even persons subject to hal- 
lucinations, like Nicolai of Berlin, learn to recognize 
the unreal character of these phantasms. On this point 
the following bit of autobiography from the pen of 
Coleridge throws an interesting light. " A lady '' (he 
writes) " once asked me if I believed in ghosts and ap- 
paritions. I answered with truth and simplicity, ' No, 
madam, I have seen far too many myself.' " 1 How- 
ever irresistible our sense-illusions may be, so long as 
we are under the sway of particular impressions or men- 
tal images, we can, when resolved to do so, undeceive 
ourselves by carefully attending to the actual state of 
things about us. And in many cases, when once the 

1 Friend, vol. i., p. 243. The story is referred to by Sir W. 
Scott in his Demonology and Witchcraft. 



126 ILLUSIONS OF PEKCEPTION. 

correction is made, the illusion seems an impossibility. 
By no effort of imagination are we able to throw our- 
selves back into the illusory mental condition. So long 
as this power of dispelling the illusion remains with 
us, we need not be alarmed at the number and variety 
of the momentary misapprehensions to which we are 
liable. 






CHAPTEE VIL 

DEEAMS. 

The phenomena of dreams may well seem at first sight 
to form a world of their own, having no discoverable 
links of connection with the other facts of human 
experience. First of all, there is the mystery of sleep, 
which quietly shuts all the avenues of sense and so 
isolates the mind from contact with the world outside. 
To gaze at the motionless face of a sleeper temporarily 
rapt from the life of sight, sound, and movement — 
which, being common to all, binds us together in 
mutual recognition and social action — has always some- 
thing awe-inspiring. This external inaction, this 
torpor of sense and muscle, how unlike to the familiar 
waking life, with its quick responsiveness and its over- 
flowing energy ! And then, if we look at dreams from 
the inside, we seem to find but the reverse face of 
the mystery. How inexpressibly strange does the late 
night-dream seem to a person on waking ! He feels he 
has been seeing and hearing things no less real than 
those of waking life ; but things which belong to an 
unfamiliar world, an order of sights and a sequence of 
events quite unlike those of waking experience ; and 



128 DREAMS. 

he asks himself in his perplexity where that once- 
visited region really lies, or by what magic power it 
was suddenly and for a moment created for his vision. 
In truth, the very name of dream suggests something 
remote and mysterious, and when we want to characterize 
some impression or scene which by its passing strange- 
ness filled us with wonder, we naturally call it dream- 
like. 

Theories of Breams. 

The earliest theories respecting dreams illustrate 
very clearly this perception of the remoteness of 
dream-life from waking experience. By the simple 
mind of primitive man this dream-world is regarded 
as similar in its nature or structure to our common 
world, only lying remote from this. The savage con- 
ceives that when he falls asleep, his second self leaves 
his familiar body and journeys forth to unfamiliar 
regions, where it meets the departed second selves of 
his dead ancestors, and so on. From this point of 
view, the experience of the night, though equal in 
reality to that of the day, is passed in a wholly dis- 
connected region. 1 

A second and more thoughtful view of dreams, 
marking a higher grade of intellectual culture, is 
that these visions of the night are symbolic pictures 
unfolded to the inner eye of the soul by some super- 
natural being. The dream-experience is now, in a 
sense, less real than it was before, since the phantasms 
that wear the guise of objective realities are simply 

1 See E. B. Tylor, Primitive Culture, ch. xi. ; cf. Herbert Spencer, 
Principles of Sociology, ch. x. 



HISTORY OF DREAM THEORIES. 129 

images spread out to the spirit's gaze, or the direct 
utterance of a divine message. Still, this mysterious 
contact of the mind with the supernatural is regarded 
as a fact, and so the dream assumes the appearance of a 
higher order of experience. Its one point of attach- 
ment to the experience of waking life lies in its 
symbolic function ; for the common form which this 
supernatural view assumes is that the dream is a dim 
prevision of coming events. Artemidorus, the great 
authority on dream interpretation (pneirocritics) for 
the ancient world, actually defines a dream as "a 
motion or fiction of the soul in a diverse form signify- 
ing either good or evil to come ; " and even a logician 
like Porphyry ascribes dreams to the influence of a 
good demon, who thereby warns us of the evils which 
another and bad demon is preparing for us. The same 
mode of viewing dreams is quite common to-day, and 
many who pride themselves on a certain intellectual 
culture, and who imagine themselves to be free from 
the weakness of superstition, are apt to talk of dreams 
as of something mysterious, if not distinctly ominous. 
Nor is it surprising that phenomena which at first 
sight look so wild and lawless, should still pass for 
miraculous interruptions of the natural order of events. 1 
Yet, in spite of this obvious and impressive element 
of the mysterious in dream-life, the scientific impulse 
to illuminate the less known by the better known has 
long since begun to play on this obscure subject. 
Even in the ancient world a writer might here and 

1 For a fuller account of the different modes of dream-interpre- 
tation, see my article " Dream," in the ninth edition of the Encyclo' 
paedia Britannica. 

7 



130 DREAMS. 

there be found, like Democritus or Aristotle, who was 
bold enough to put forward a natural and physical 
explanation of dreams. But it has been the work of 
modern science to provide something like an approxi- 
mate solution of the problem. The careful study of 
mental life in its intimate union with bodily opera- 
tions, and the comparison of dream-combinations with 
other products of the imagination, normal as well as 
morbid, have gradually helped to dissolve a good part 
of the mystery which once hung like an opaque mist 
about the subject. In this way, our dream-operations 
have been found to have a much closer connection 
with our waking experiences than could be supposed 
on a superficial view. The materials of our dreams 
are seen, when closely examined, to be drawn from 
our waking experience. Our waking consciousness 
acts in numberless ways on our dreams, and these 
again in unsuspected ways influence our waking mental 
life. 1 Not only so, it is found that the quaint chaotic 
play of images in dreams illustrates mental processes 
and laws which are distinctly observable in waking 
thought. Thus, for example, the apparent objective 
reality of these visions has been accounted for, without 
the need of resorting to any supernatural agency, in the 
lio-ht of a vast assemblage of facts gathered from 
the by-ways, so to speak, of waking mental life. I 
need hardly add that I refer to the illusions of sense 
dealt with in the foregoing chapters. 

Dreams are to a large extent the semblance of 

1 For a fuller account of the reaction of dreams on waking con- 
sciousness, see Paul Radestock, Schlaf unci Traum. The subject ia 
touched on later, under the Illusions of Memory, 



PHYSIOLOGY OF SLEEP. * 131 

external perceptions. Other psychical phenomena, as 
self-reflection, emotional activity, and so on, appear 
in dream-life, but they do so . in close connection with 
these quasi-perceptions. The name "vision," given 
by old writers to dreams, sufficiently points out this 
close affinity of the mental phenomena to sense-per- 
ception ; and so far as science is concerned, they 
must be regarded as a peculiar variety of sense- 
illusion. Hence the appropriateness of studying them 
in close connection with the illusions of perception 
of the waking state. Though marked off by the 
presence of very exceptional physiological conditions, 
they are largely intelligible by help of these physio- 
logical and psychological principles which we have 
just been considering. 

The State of Sleep. 

The physiological explanation of dreams must, 
it is plain, set out with an account of the condition of 
the organism known as sleep. While there is here 
much that is uncertain, there are some things which 
are fairly well known. Eecent physiological observa- 
tion has gone to prove that during sleep all the 
activities of the organism are appreciably lowered. 
Thus, for example, according to Testa, the pulse falls 
by about one-fifth. This lowering of the organic func- 
tions appears, under ordinary circumstances, to increase 
towards midnight, after which there is a gradual rising. 

The nervous system shares in this general depression 
of the vital activities. The circulation being slower, 
the process of reparation and nutrition of the nerves is 
retarded, and so their degree of excitability diminished. 



132 ■ DREAMS. 

This is clearly seen in the condition of the peripheral 
regions of the nervous system, including the sense- 
organs, which appear to be but very slightly acted on 
by their customary stimuli. 

The nervous centres must participate in this 
lethargy of the system. In other words, the activity of 
the central substance is lowered, and the result of this 
is plainly seen in what is usually thought of as the 
characteristic feature of sleep, namely, a transition 
from vigorous mental activity or intense and clear 
consciousness, to comparative inactivity or faint and 
obscure consciousness. The cause of this condition of 
the centres is supposed to be the same as that of the 
torpidity of all the other organs in sleep, namely, the 
retardation of the circulation. But, though there is no 
doubt as to this, the question of the proximate physio- 
logical conditions of sleep is still far from being settled. 
Whether during sleep the blood-vessels of the brain are 
fuller or less full than during waking, is still a moot 
point. Also the qualitative condition of the blood in 
the cerebral vessels is still a matter of discussion. 1 

Since the effect of sleep is to lower central activity, 
the question naturally occurs whether the nervous 
centres are ever rendered inactive to such an extent as 
to interrupt the continuity of our conscious life. This 
question has been discussed from the point of view of 
the metaphysician, of the psychologist, and of the phy- 
siologist, and in no case is perfect unanimity to be 
found. The metaphysical question, whether the soul 
as a spiritual substance is capable of being wholly in- 

1 For an account of the latest physiological hypotheses as to the 
proximate cause of sleep, see Eadestock, op. cit., appendix. 



IS SLEEP EVEE DREAMLESS? 183 

active, or whether it is not in what seem the moments 
of profoundest unconsciousness partially awake — the 
question so warmly discussed by the Cartesians, Leib- 
nitz, etc. — need not detain us here. 

Of more interest to us are the psychological and 
the physiological discussions. The former seeks to 
settle the question by help of introspection and memory. 
On the one side, it is urged against the theory of un- 
broken mental activity, that we remember so little of 
the lowered consciousness of sleep. 1 To this it is replied 
that our forgetfulness of the contents of dream-con- 
sciousness, even if this were unbroken, would be fully 
accounted for by the great dissimilarity between dream- 
ing and waking mental life. It is urged, moreover, 
on this side that a sudden rousing of a man from sleep 
always discovers him in the act of dreaming, and that 
this goes to prove the uniform connection of dreaming 
and sleeping. This argument, again, may be met by 
the assertion that our sense of the duration of our 
dreams is found to be grossly erroneous ; that, owing to 
the rapid succession of the images, the realization of 
which would involve a long duration, we enormously 
exaggerate the length of dreams in retrospection. 2 
From this it is argued that the dream which is recalled 
on our being suddenly awakened may have had its 
whole course during the transition state of waking. 

Again, the fact that a man may resolve, on going to 
sleep, to wake at a certain hour, has often been cited in 

1 Plutarch, Locke, and others give instances of people who never 
dreamt. Lessing asserted of himself that he never knew what it was 
to dream. 

2 The error touched on here will be fully dealt with xmder 
Illusions of Memory. 



134 DREAMS. 

proof of the persistence of a degree of mental activity 
even in perfectly sound sleep. The force of this con- 
sideration, however, has been explained away by saying 
that the anticipation of rising at an unusual hour 
necessarily produces a slight amount of mental dis- 
quietude, which is quite sufficient to prevent sound 
sleep, and therefore to expose the sleeper to the rousing 
action of faint external stimuli. 

While the purely psychological method is thus 
wholly inadequate to solve the question, physiological 
reasoning appears also to be not perfectly conclusive. 
Many physiologists, not unnaturally desirous of up- 
setting what they regard as a gratuitous metaphysical 
hypothesis, have pronounced in favour of an absolutely 
dreamless or unconscious sleep. From the physio- 
logical point of view, there is no mystery in a totally 
suspended mental activity. On the other hand, there 
is much to be said on the opposite side, and perhaps 
it may be contended that the purely physiological 
evidence rather points to the conclusion that central 
activity, however diminished during sleep, always 
retains a minimum degree of intensity. At least, one 
would be disposed to argue in this way from the 
analogy of the condition of the other functions of the 
organism during sleep. Possibly this modicum of 
positive evidence may more than outweigh any slight 
presumption against the doctrine of unbroken mental 
activity drawn from the negative circumstance that we 
remember so little of our dream-life. 1 

Such being the state of physiological knowledge 

1 For a very full, fair, and thoughtful discussion of this whole 
question, see Rarlestock, op. cit., ch. iv. 



STATE OF NEKVE-STEUCTURES IN SLEEP. 135 

respecting the immediate conditions of sleep, we can- 
not look for any certain information on the nature of 
that residual mode of cerebral activity which manifests 
itself subjectively in dreams. It is evident, indeed, 
that this question can only be fully answered when the 
condition of the brain as a whole during sleep is under- 
stood. Meanwhile we must be content with vague 
hypotheses. 

It may be said, for one thing, that during sleep the 
nervous substance as a whole is less irritable than 
during waking hours. That is to say, a greater amount 
of stimulus is needed to produce any conscious result. 1 
This appears plainly enough in the case of the 
peripheral sense-organs. Although these are not, as it 
is often supposed, wholly inactive during sleep, they 
certainly require a more potent external stimulus to 
rouse them to action. And what applies to the 
peripheral regions applies to the centres. In truth, 
it is clearly impossible to distinguish between the 
diminished irritability of the peripheral and that of 
the central structures. 

At first sight it seems contradictory to the above 
to say that stimuli which have little effect on the 
centres of consciousness during waking life produce an 
appreciable result in sleep. Nevertheless, it will be 
found that this is the case. Thus organic processes 
which scarcely make themselves known to the mind in 
a waking state, may be shown to be the originators of 
many of our dreams. This fact can only be explained 
on the physical side by saying that the special cerebral 

1 This may be technically expressed by saying that the lirninal 
intensity (Schwelle) is raised during sleep. 



136 DREAMS. 

activities engaged in an act of attention are greatly 
liberated during sleep by the comparative quiescence 
of the external senses. These activities, by co-operat- 
ing with the faint results of the stimuli coming from 
the internal organs, serve very materially to increase 
their effect. 

Finally, it is to be observed that, while the centres 
thus respond with diminished energy to peripheral 
stimuli, external and internal, they undergo a direct, 
or " automatic," mode of excitation, being roused into 
activity independently of an incoming nervous im- 
pulse. This automatic stimulation has been plausibly 
referred to the action of the products of decomposition 
accumulating in the cerebral blood-vessels. 1 It is pos- 
sible that there is something in the nature of this 
stimulation to account for the force and vividness of its 
conscious results, that is to say, of dreams. ' • 

The Dream State. 

Let us now turn to the psychic side of these con- 
ditions, that is to say, to the general character of the 
mental states known as dreams. It is plain that the 
closing of the avenues of the external senses, which is 
the accompaniment of sleep, will make an immense 
difference in the mental events of the time. Instead 
of drawing its knowledge from without, noting its 
bearings in relation to the environment, the mind will 
now be given over to the play of internal imagination. 
The activity of fancy will, it is plain, be unrestricted by 
collision with external fact. The internal mental life 
will expand in free picturesque movement. 

1 See Wundt, riiysidogische rsijcliologie, pp. 188-191. 



STATURE OF DREAM-ACTIVITY. 137 

To say that in sleep the mind is given over to its 
own imaginings, is to say that the mental life in these 
circumstances will reflect the individual temperament 
and mental history. For the play of imagination at 
any time follows the lines of our past experience more 
closely than would at first appear, and being coloured 
with emotion, will reflect the predominant emotional 
impulses of the individual mind. Hence the saying 
of Heraclitus, that, while in waking we all have a com- 
mon world, in sleep we have each a world of our own. 

This play of imagination in sleep is furthered by 
the peculiar attitude of attention. When asleep the 
voluntary guidance of attention ceases ; its direction is 
to a large extent determined by the contents of the 
mind at the moment. Instead of holding the images 
and ideas, and combining them according to some 
rational end, the attention relaxes its energies and 
succumbs to the force of imagination. And thus, in 
sleep, just as in the condition of reverie or day-dream- 
ing, there is an abandonment of the fancy to its own 
wild ways. 

It follows that the dream-state will not appear to 
the mind as one of fancy, but as one of actual percep- 
tion, and of contact with present reality. Dreams are 
clearly illusory, and, unlike the illusions of waking life, 
are complete and persistent. 1 And the reason of this 
ought now to be clear. First of all, the mind during 
sleep wants what M. Taine calls the corrective of a pre- 

1 There is, indeed, sometimes an undertone of critical reflection, 
•which is sufficient to produce a feeling of uncertainty and bewilder- 
ment, and in very rare cases to amount to a vague consciousness that 
the mental experience is a dream. 



138 DREAMS. 

sent sensation. When awake under ordinary circum- 
stances, any momentary illusion is at once set right by 
a new act of orientation. The superior vividness of the 
external impression cannot leave us in any doubt, 
when calm and self-possessed, whether our mental 
images answer to present realities or not. On the 
other hand, when asleep, this reference to a fixed 
objective standard is clearly impossible. Secondly, we 
may fairly argue that the mental images of sleep 
approximate in character to external impressions. This 
they do to some extent in point of intensity, for, in 
spite of the diminished excitability of the centres, the 
mode of stimulation which occurs in sleep may, as I 
have hinted, involve an energetic cerebral action. 
And, however this be, it is plain that the image 
will gain a preternatural force through the greatly 
narrowed range of attention. When the mind of the 
sleeper is wholly possessed by an image or group of 
images, and the attention kept tied down to these, 
there is a maximum reinforcement of the images. 
But this is not all. When the attention is thus held 
captive by the image, it approximates in character to 
an external impression in another way. In our waking 
state, when our powers of volition are intact, the 
external impression is characterized by its fixity or its 
obdurate resistance to our wishes. On the other hand, 
the mental image is fluent, accommodating, and dis- 
appears and reappears according to the direction of our 
volitions. In sleep, through the suspension of the 
higher voluntary power of attention, the mental image 
seems to lord it over our minds just as the actual 
impression of waking life. 



DREAM AS SENSE-ILLUSION. 139 

This much may suffice, perhaps, by way of a 
general description of the sleeping and dreaming state. 
Other points will make themselves known after we 
have studied the contents and structure of dreams in 
detail. 

Dreams are commonly classified {e.g. by Wundt)with 
hallucinations, and this rightly, since, as their common 
appellation of " vision " suggests, they are for the most 
part the semblauce of percepts in the absence of ex- 
ternal impressions. At the same time, recent research 
goes to show that in many dreams something answer- 
ing to the " external impression " in waking perception 
is the starting-point. Consequently, in order to be 
as accurate as possible, I shall divide dreams into 
illusions (in the narrow sense) and hallucinations. 

Dream-Illusions. 

By dream-illusions I mean those dreams which set 
out from some peripheral nervous stimulation, internal 
or external. That the organic processes of digestion, 
respiration, etc., act as stimuli to the centres in sleep 
is well known. Thus, David Hartley assigns as the 
second great source of dreams " states of the body." 1 
But it is not so well known to what an extent our 
dreams may be influenced by stimuli acting on the 
exterior sense-organs. Let us first glance at the 
action of such external stimuli. 

Action of External Stimuli. 

During sleep the eyes are closed, and consequently 
the action of external light on the retina impeded. 

' Observations on Man, Part I. ch. iii. sec. 5. 



140 DEEAMS. 

Yet it is found that even under these circumstances 
any very bright light suddenly introduced is capable 
of stimulating the optic fibres, and of affecting conscious- 
ness. The most common form of this is the effect of 
bright moonlight, and of the early sun's rays. Krauss 
tells a funny story of his having once, when twenty-six 
years old, caught himself, on waking, in the act of 
stretching out his arms towards what his dream-fancy 
had pictured as the image of his mistress. When 
fully awake, this image resolved itself into the full 
moon. 1 It is not improbable, as Eadestock remarks, 
that the rays of the sun or moon are answerable for 
many of the dreams of celestial glory which persons of 
a highly religious temperament are said to experience. 
External sounds, when not sufficient to rouse the 
sleeper, easily incorporate themselves into his dreams. 
The ticking of a watch, the stroke of a clock, the hum 
of an insect, the song of a bird, the patter of rain, are 
common stimuli to the dream-phantasy. M. Alf. 
Maury tells us, in his interesting account of the series 
of experiments to which he submitted himself in order 
to ascertain the result of external stimulation on the 
mind during sleep, that when a pair of tweezers was 
made to vibrate near his ear, he dreamt of bells, the 
tocsin, and the events of June, 1848. 2 Most of us, 
probably, have gone through the experience of im- 
politely falling asleep when some one was reading to 
us, and of having dream-images suggested by the 
sounds that were still indistinctly heard. Schemer 
gives an amusing case of a youth who was permitted to 

1 Quoted by Eadestock, op. cit., p. 110. 

2 Le Sommeil et les Beves, p. 132, et seq. 



ACTION OF EXTERNAL STIMULI. 141 

whisper his name into the ear of his obdurate mistress, 
the consequence of which was that the lady contracted 
a habit of dreaming about him, which led to a felicitous 
change of feeling on her part. 1 

The two lower senses, smell and taste, seem to 
play a less important part in the production of dream- 
illusions. Eadestock says that the odour of flowers 
in a room easily leads to visual images of hot-houses, 
perfumery shops, and so on ; and it is probable that 
the contents of the mouth may occasionally act as a 
stimulus to the organ of taste, and so give rise to 
corresponding dreams. As Eadestock observes, these 
lower sensations do not commonly make known their 
quality to the sleeper's mind. They become trans- 
formed at once into visual, instead of into olfactory or 
gustatory percepts. That is to say, the dreamer does 
not imagine himself smelling or tasting, but seeing an 
object. 

The contact of objects with the tactual organ is 
one of the best recognized causes of dreams. M. Maury 
found that when his lips were tickled, his dream-fancy 
interpreted the impression as of a pitch plaster being 
torn off his face. An unusual pressure on any part 
of the body, as, for example, from contact with a 
fellow-sleeper, is known to give rise to a well-marked 
variety of dream. Our own limbs may even appear 
as foreign bodies to our dream-imagination, when 
through pressure they become partly paralyzed. Thus, 
on one occasion, I awoke from a miserable dream, in 
which I felt sure I was grasping somebody's hand in 

1 Das Leben des Traumes, p. 369. Other instances are related by 
Beattie and Abercrombie. 



142 



DREAMS. 



bed, and I was racked by terrifying conjectures as to who 
it might be. When fully awake, I discovered that I 
had been lying on my right side, and clasping the wrist 
of the right arm (which had been rendered insensible 
by the pressure of the body) with the left hand. 

In close connection with these stimuli of pressure 
are those of muscular movement, whether unimpeded 
or impeded. We need not enter into the difficult 
question how far the "muscular sense" is connected 
with the activity of the motor nerves, and how far with 
sensory fibres attached to the muscular or the adjacent 
tissues. Suffice it to say that an actual movement, a 
resistance to an attempted movement, or a mere dis- 
disposition to movement, whether consequent on a 
surplus of motor energy or on a sensation of discomfort 
or fatigue in the part to be moved, somehow or other 
makes itself known to our minds, even when we are 
deprived of the assistance of vision. And these feel- 
ings of movement, impeded or unimpeded, are common 
initial impulses in our dream-experiences. It is quite 
a mistake to suppose that dreams are built up out of 
the purely passive sensations of sight and hearing. A 
close observation will show that in nearly every dream 
we imagine ourselves either moving among the objects 
we perceive or striving to move when some weighty 
obstacle obstructs us. All of us are familiar with the 
common forms of nightmare, in which we strive hope- 
lessly to flee from some menacing evil, and this dream- 
experience, it may be presumed, frequently comes from 
a feeling of strain in the muscles, due to an awkward 
disposition of the limbs during sleep. The common 
dream-illusion of falling down a vast abyss is plausibly 



SS 



SUBJECTIVE STIMULATION OF NERVES. 143 

referred by Wundt to an involuntary extension of the 
foot of the sleeper. 

Action of Internal Stimuli. 

Let ns now pass from the action of stimuli lying 
outside the organism, to that of stimuli lying within 
the peripheral regions of the sense-organs. I have 
already spoken of the influence of subjective sen- 
sations of sight, hearing, etc., on the illusions of 
waking life, and it is now to be added that these sen- 
sations play an important part in our dream-life. 
Johannes Miiller lays great prominence on the part 
taken by ocular spectra in the production of dreams. 
As he observes, the apparent rays of light, light- 
patches, mists of light, and so on, due to changes of 
blood-pressure in the retina, only manifest themselves 
clearly when the eyes are closed and the more powerful 
effect of the external stimulus cut off. These sub- 
jective spectra come into prominence in the sleepy 
condition, giving rise to what M. Maury calls " hal- 
lucinations hypnagogiques," and which he regards 
(after Gruithuisen) as the chaos out of which the dream- 
cosmos is evolved. 1 They are pretty certainly the 
starting-point in those picturesque dreams in which 
figure a number of bright objects, such as beautiful 
birds, butterflies, flowers, or angels. 

That the visual images of our sleep do often involve 
the peripheral regions of the organ of sight, seems to 
be proved by the singular fact that they sometimes 
persist after waking. Spinoza and Jean Paul Eichter 

1 Le Sommeil et les Heces, p. 42, et seq. 



144 DEEAMS. 

both experienced this survival of dream-images. Still 
more pertinent is the fact that the effects of retinal 
fatigue are producible by dream-images. The physio- 
logist Gruithuisen had a dream, in which the principal 
feature was a violet flame, and which left behind it, 
after ivahing, for an appreciable duration, a comple- 
mentary image of a yellow spot. 1 

Subjective auditory sensations appear to be much 
less frequent causes of dream-illusions than correspond- 
ing visual sensations. Yet the rushing, roaring sound 
caused by the circulation of the blood in the ear is, 
probably, a not uncommon starting-point in dreams. 
With respect to subjective sensations of smell and 
taste, there is little to be said. On the other hand, 
subjective sensations due to varying conditions in the 
skin are a very frequent exciting cause of dreams. 
Variations in the state of tension of the skin, brought 
about by alteration of position, changes in the charac- 
ter of the circulation, the irradiation of heat to the 
skin or the loss of the same, chemical changes, — ■ 
these are known to give rise to a number of familiar 
sensations, including those of tickling, itching, burning, 
creeping, and so on ; and the effects of these sensations 
are distinctly traceable in our dreams. For example, 
the exposure of a part of the body through a loss of 
the bed-clothes is a frequent excitant of distressing 
dreams. A cold foot suggests that the sleeper is walk- 
ing over snow or ice. On the other hand, if the cold 
foot happens to touch a v a m part of the body, the 

1 Beitrage sur Physiognosie und Heautognosie, p. 25S. For other 
cases see H. Meyer, Physiologie der Nervenfaser, p. 309; and Striimpell, 
Die Natur und Entsteliung der Traume, p. 125. 



INFLUENCE OF OEGANIO SENSATIONS. 145 

dream-fancy constructs images of walking on burning 
lava, and so on. 

These sensations of the skin naturally conduct us ; 
to the organic sensations as a whole ; that is to say, the 
feelings connected with the varying condition of the 
bodily organs. These include the feelings which arise 
in connection with the processes of digestion, respiration, 
and circulation, and the condition of various organs 
according to their state of nutrition, etc. During our 
waking life these organic feelings coalesce for the most 
part, forming as the " vital sense " an obscure back- 
ground for our clear discriminative consciousness, and 
only come forward into this region when very excep- 
tional in character, as when respiration or digestion is 
impeded, or when we make a special effort of attention 
to single them out. 1 When we are asleep, however, and 
the avenues of external perception are closed, they 
assume greater prominence and distinctness. The 
centres, no longer called upon to react on stimuli coming 
from without the organism, are free to react on stimuli 
coming from its hidden recesses. So important a part, 
indeed, do these organic feelings take in the dream- 
drama, that some writers are disposed to regard them 
as the great, if not the exclusive, cause of dreams. 
Thus, Schopenhauer held that the excitants of dreams 
are impressions received from the internal regions of 
the organism through the sympathetic nervous system. 2 

1 A very clear and full account of these organic sensations, or 
common sensations, has recently appeared from the pen of A. Horwicz 
in the Vierteljahrsschrift fur wistenschaftliche Philosophie, iv. Jahrgang 
3tes Heft. 

2 Schopenhauer uses this hypothesis in order to account for tho 
apparent reality of dream-illusions. He thinks these internal sensa- 



146 DREAMS. 

It is hardly necessary, perhaps, to give many illus- 
trations of the effect of such organic sensations on our 
dreams. Among the most common provocatives of 
dreams are sensations connected with a difficulty in 
breathing, due to the closeness of the air or to the 
pressure of the bed-clothes on the mouth. J. Borner 
investigated the influence of these circumstances by 
covering with the bed-clothes the mouth and a part of 
the nostrils of persons who were sound asleep. This 
was followed by a protraction of the act of breathing, a 
reddening of the face, efforts to throw off' the clothes, etc. 
On being roused, the sleeper testified that he had ex- 
perienced a nightmare, in which a horrid animal seemed 
to be weighing him down. 1 Irregularity of the heart's 
action is also a frequent cause of dreams. It is not 
improbable that the familiar dream-experience of flying 
arises from disturbances of the respiratory and circulatory 
movements. 

Again, the effects of indigestion, and more particu- 
larly stomachic derangement, on dreams are too well 
known to require illustration. It may be enough to 
allude to the famous dream which Hood traces to an 
excessive indulgence at supper. It is known that the 
varying condition of the organs of secretion influences 
our dream-fancy in a number of ways. 

Finally, it is to be observed that an injury done to 
any part of the organism is apt to give rise to appro- 

tiona may be transformed by the " intuitive function " of the brain (by 
means of the "forms" of space, time, etc.) into quasi-real ities, just as 
well as the subjective sensations of light, sound, etc., which arise in 
the organs of sense in the absence of external stimuli. (See Versuch 
iiber das Geistersehen : Werke, vol. v. p. 2±4, et seq.) 
1 Das Alpdruclcen, pp. 8, 9, 27. 



EXAGGERATION OF SENSATION. 147 

priate dream-images. Iu this way, very slight disturb- 
ances which would hardly affect waking consciousness 
may make themselves felt during sleep. Thus, for 
example, an incipient toothache has been known to 
suggest that the teeth are being extracted. 1 

It is worth observing that the interpretation of 
these various orders of sensations by the imagination 
of the dreamer takes very different forms according 
to the person's character, previous experience, ruling 
emotions, and so on. This is what is meant by saying 
that during sleep every man has a world of his own, 
whereas, when awake, he shares in the common world of 
perception. 

Bream-Exaggeration. 

It is to be noticed, further, that this interpretation 
of sensation during sleep is uniformly a process of exag- 
geration. 2 The exciting causes of the feeling of dis- 
comfort, for example, are always absurdly magnified. 
The reason of this seems to be that, owing to the con- 
dition of the mind during sleep, the nature of the 
sensation is not clearly recognizable. Even in the 
case of familiar external impressions, such as the sound 
of the striking of a clock, there appears to be wanting 
that simple process of reaction by which, in a waking 
condition of the attention, a sense-impression is instantly 
discriminated and classed. In sleep, as in the artifi- 

1 It is this fact which justifies writers in assigning a prognostic 
character to dreams. 

2 A part of the apparent exaggeration in our dream-experiences 
may be retrospective, and due to the effect of the impression of wonder 
which they leave behind them. (See StrUmpell, Die Natur und 
Entstehung der Triiume.) 



148 DEEAMS. . 

cially induced hypnotic condition, the slighter differ- 
ences of quality among sensations are not clearly 
recognized. The activity of the higher centres, which 
are concerned in the finer processes of discrimination 
and classification, being greatly reduced, the impres- 
sion may be said to come before consciousness as 
something novel and unfamiliar. And just as we saw 
that in waking life novel sensations agitate the mind, 
and so lead to an exaggerated mode of interpretation; 
so here we see that what is unfamiliar disturbs the 
mind, rendering it incapable of calm attention and 
just interpretation. 

This failure to recognize the real nature of an 
impression is seen most conspicuously in the case of 
the organic sensations. As I have remarked, these con- 
stitute for the most part, in waking life, an undiscrimi- 
nated mass of obscure feeling, of which we are only 
conscious as the mental tone of the hour. And in the 
few instances in which we do attend to them separately, 
whether through their exceptional intensity or in con- 
sequence of an extraordinary effort of discriminative 
attention, we can only be said to perceive them, that is, 
recognize their local origin, very vaguely. Hence, when 
asleep, these sensations get very oddly misinterpreted. 

The localization of a bodily sensation in waking life 
means the combination of a tactual and a visual image 
with the sensation. Thus, my recognition of a twinge 
of toothache as coming from a certain tooth, involves 
representations of the active arid passive sensations 
which touching and looking at the tooth would yield 
me. That is to say, the feeling instantly calls up 
a compound mental image exactly answering to a 



DEEAM-SYMBOLISM. 149 

visual percept. This holds good in dream-interpre- 
tation too; the interpretation is effected by means of 
a visual image. But since the feeling is only very 
vaguely recognized, this visual image does not answer 
to the bodily part concerned. Instead of this, the 
fancy of the dreamer constructs some visual image 
which bears a vague resemblance to the proper one, and 
is generally, if not always, an exaggeration of this in 
point of extensive magnitude, etc. For example, a 
sensation arising from pressure on the bladder, being 
dimly connected with the presence of a fluid, calls up 
an image of a flood, and so on. 

This mode of dream-interpretation has by some 
writers been erected into the typical mode, under the 
name of dream-symbolism. Thus Schemer, in his 
interesting though somewhat fanciful work, Das Leben 
des Traumes, contends that the various regions of the 
body regularly disclose themselves to the dream-fancy 
under the symbol of a building or group of buildings ; 
a pain in the head calling up, for example, the image 
of spiders on the ceiling, intestinal sensations exciting 
an image of a narrow alley, and so on. Such theories are 
clearly an exaggeration of the fact that the localization 
of our bodily sensations during sleep is necessarily 
imperfect. 1 

In many cases the image called up bears on its 
objective side no discoverable resemblance to that of 
the bodily region or the exciting cause of the sensation. 
Here the explanation must be looked for in the sub- 
jective side of the sensation and mental image, that is 
to say, in their emotional quality, as pleasurable or 
1 Cf. Eadestock, op. cit., pp. 131, 132. 



150 DREAMS. 

painful, distressing, quieting, etc. It is to be observed, 
indeed, that in natural sleep, as in the condition known 
as hypnotism, while differences of specific quality in 
the sense-impressions are lost, the broad difference of 
the pleasurable and the painful is never lost. It is, in 
fact, the subjective emotional side of the sensation that 
uniformly forces itself into consciousness. This being 
so, it follows that, speaking generally, the sensations of 
sleep, both external and internal, or organic, will be 
interpreted by what G. H. Lewes has called "an 
analogy of feeling;" that is to say, by means of a 
mental image having some kindred emotional character 
or colouring. 

Now, the analogy between the higher emotional 
and the bodily states is a very close one. A sensation 
of obstruction in breathing has its exact analogue in 
a state of mental embarrassment, a sensation of itching 
its counterpart in mental impatience, and so on. And 
since these emotional experiences are deeper and 
fuller than the sensations, the tendency to exaggerate 
the nature and causes of these last would naturally 
lead to an interpretation of them by help of these 
experiences. In addition to this, the predominance of 
visual imagery in sleep would aid this transformation 
of a bodily sensation into an emotional experience, 
since visual perceptions have, as their accompaniments 
of pleasure and pain, not sensations, but emotions. 1 

1 I was on one occasion able to observe this piocess going on in 
the transition from waking to sleeping. I partly fell asleep when 
suffering from toothache. Instantly the successive throbs of pain 
transformed themselves into a sequence of visible movements, which 
I can only vaguely describe as the forward strides of some menacing 
adversary. 



CENTEAL DREAM- EXCITANTS. 151 

Since in this vague interpretation of bodily- 
sensation the actual impression is obscured, and not 
taken up as an integral part into the percept, it is 
evident that we cannot, strictly speaking, call the 
process an imitation of an act of perception, that is to 
say, an illusion. And since, moreover, the visual 
image by which the sensation is thus displaced 
appears as a present object, it would, of course, be 
allowable to speak of this as an hallucination. This 
substitution of a more or less analogous visual image 
for that appropriate to the sensation forms, indeed, a 
transition from dream-illusion, properly so called, to 
dream-hallucination. 

Dream Hallucinations. \, 

On the physical side, these hallucinations answer 
to cerebral excitations which are central or automatic, 
not depending on movements transmitted from the 
periphery of the nervous system. Of these stimula- 
tions some appear to be direct, and due to unknown 
influences exerted by the state of nutrition of the 
cerebral elements, or the action of the contents of the 
blood-vessels on these elements. 

Effects of Direct Central Stimulation. 

That such action does prompt a large number of 
dream-images may be regarded as fairly certain. First 
of all, it seems impossible to account for all the images 
of dream-fancy as secondary phenomena connected by 
links of association with the foregoing classes of sensa- 
tion. However fine and invisible many of the threads 
which hold together our ideas may be, they will hardly 



152 DREAMS. 

explain the profusion and picturesque variety of dream- 
imagery. Secondly, as are able in certain cases to 
infer with a fair amount of certainty that a dream- 
image is due to such central stimulation. The common 
occurrence that we dream of the more stirring events, 
the anxieties and enjoyments of the preceding day, 
appears to show that when the cerebral elements are 
predisposed to a certain kind of activity, as they are 
after n*» ring been engaged for some time in this par- 
ticular work, they are liable to be excited by some 
stimulus brought directly to bear on them during 
sleep. And if this is so, it is not improbable that 
many of the apparently forgotten images of persons 
and places which return with such vividness in dreams 
are excited by a mode of stimulation which is for the 
greater part confined to sleep. I say " for the greater 
part," because even in our indolent, listless moments of 
waking existence such seemingly forgotten ideas some- 
times return as though by a spontaneous movement 
of their own and by no discoverable play of association. 
It may be well to add that this immediate revival 
of impressions previously received by the brain includes 
not only the actual perceptions of waking life, but also 
the ideas derived from others, the ideal fancies supplied 
by works of fiction, and even the images which our un- 
aided waking fancy is wont to shape for itself. Our daily 
conjectures as to the future, the communications to us 
by others of their thoughts, hopes, and fears, — these 
give rise to numberless vague fugitive images, any 
one of which may become distinctly revived in sleep. 1 

1 Even the " unconscious impressions " of waking hours, that is to 
say, those impressions which are so fugitive as to leave no psychical 



REVIVAL OF IMAGES IN DREAMS. 153 

This throws light on the curious fact that we often 
dream of experiences and events quite unlike those of 
our individual life. Thus, for example, the common 
construction by the dream-fancy of the experience of 
flight in mid-air, and the creation of those weird 
forms which the terror of a nightmare is wont to 
bring in its train, seem to point to the past action of 
waking fancy. To imagine one's self flying when 
looking at a bird is probably a common action with 
all persons, at least in their earlier years, and images 
of preternaturally horrible beings are apt to be sup- 
plied to most of us some time during life by nurses or 
by books. 

Indirect Central Stimulation. 

Besides these direct central stimulations, there 
are others which, in contradistinction, may be called 
indirect, depending on some previous excitation. 
These are, no doubt, the conditions of a very large 
number of our dream-images. There must, of course, 
be some primary cerebral excitation, whether that of a 
present peripheral stimulation, or that which has been 
termed central and spontaneous ; but when once this 
first link of the imaginative chain is supplied, other 
links may be added in large numbers through the 
operation of the forces of association. One may, indeed, 
safely say that the large proportion of the contents of 
every dream arise in this way. 

trace behind, may thus rise into the clear light of consciousness during 
sleep. Maury relates a curious dream of his own, in which there 
appeared a figure that seemed quite strange to him, though he after- 
wards found that he must have been in the habit of meeting the 
original in a street through which he was accustomed to walk (loa 
cit., p. 124). 

8 



154 DREAMS. 

The very simplest type of dream excited by a 
present sensation contains these elements. To take an 
example, I once dreamt, as a consequence of the loud 
barking of a dog, that a dog approached me when 
lying down, and began to lick my face. Here the play 
of the associative forces was apparent : a mere sensation 
of sound called up the appropriate visual image, this 
again the representation of a characteristic action, and 
so on. So it is with the dreams whose first impulse is 
some central or spontaneous excitation. A momentary 
sight of a face or even the mention of a name during 
the preceding day may give the start to dream-activity ; 
but all subsequent members of the series of images owe 
their revival to a tension, so to speak, in the fine threads 
which bind together, in so complicated a way, our im- 
pressions and ideas. 

Among the psychic accompaniments of these 
central excitations visual images, as already hinted, 
fill the most conspicuous place. Even auditory images, 
though by no means absent, are much less numerous 
than visual. Indeed, when there are the conditions 
for the former, it sometimes happens that the auditory 
effect transforms itself into a visual effect. An illus- 
tration of this occurred in my own experience. Trying 
to fall asleep by means of the well-known device of 
counting, I suddenly found myself losing my hold on 
the faint auditory effects, my imagination transforming 
them into a visual spectacle, under the form of a path 
of light stretching away from me, in which the numbers 
appeared under the grotesque form of visible objects, 
tumbling along in glorious confusion. 

Next to these visual phantasms, certain motor 



REVIVAL BY WAY OF ASSOCIATION. 155 

hallucinations seem to be most prominent in dreams. 
By a motor hallucination, I mean the illusion that 
we are actually moving when there is no peripheral 
excitation of the motor organ. Just as the centres 
concerned in passive sensation are susceptible of 
central stimulation, so are the centres concerned 
in muscular sensation. A mere impulse iu the centres 
of motor innervation (if we assume these to be the 
central seat of the muscular feelings) may suffice to 
give rise to a complete representation of a fully 
executed movement. And thus in our sleep we seem 
to walk, ride, float, or fly. 

The most common form of motor hallucination is 
probably the vocal. In the social encounters which 
make up so much of our sleep-experience, we are wont 
to be very talkative. Now, perhaps, we find ourselves 
zealously advocating some cause, now very fierce in 
denunciation, now very amusing in witty repartee, and 
so on. This imagination of ourselves as speaking, as 
distinguished from that of hearing others talking, must, 
it is clear, involve the excitation of the structures 
engaged in the production of the muscular feelings 
which accompany vocal action, as much as, if not more 
than, the auditory centres. And the frequency of this 
kind of dream-experience may be explained, like that 
of visual imagery, by the habits of waking life. The 
speech impulse is one of the most deeply rooted of all 
our impulses, and one which has been most frequently 
exercised in waking life. 



156 DREAMS. 

Combination of Brtam-Elements. 

It is commonly said that dreams are a grotesque 
dissolution of all order, a very chaos and whirl of 
images without any discoverable connection. On the 
other hand, a few writers claim for the mind in sleep 
a power of arranging and grouping its incongruous 
elements in definite and even life-like pictures. 
Each of these views is correct within certain limits ; 
that is to say, there are dreams in which the strangest 
disorder seems to prevail, and others in which one 
detects the action of a central control. Yet, speaking 
generally, sequences of dream-images will be found to 
be determined by certain circumstances and laws, and 
so far not to be haphazard or wholly chaotic. We 
have now to inquire into the laws of these successions ; 
and, first of all, we may ask how far the known laws 
of association, together with the peculiar conditions of 
the sleeping state, are able to account for the various 
modes of dream-combination. We have already re- 
garded mental association as furnishing a large 
additional store of dream-imagery; we have now to 
consider it as explaining the sequences and concatena- 
tions of our dream-elements. 

Incoherence of Breams. 

First of all, then, let us look at the chaotic and 
apparently lawless side of dreaming, and see whether 
any clue is discoverable to the centre of this labyrinth. 
In the case of all the less elaborately ordered dreams, 
in which sights and sounds appear to succeed one 
another in the wildest dance (which class of dreams 






i 



HOW DREAM-ELEMENTS COMBINE. 157 

probably belongs to the deeper stages of sleep), the 
mind may with certainty be regarded as purely 
passive, and the mode of sequence may be referred to 
the action of association complicated by the ever- 
recurring introduction of new initial impulses, both 
peripheral and central. These are the dreams in which 
we are conscious of being perfectly passive, either as 
spectators of a strange pageant, or as borne away by 
some apparently extraneous force through a series of 
the most diverse experiences. The flux of images in 
these dreams is very much the same as that in certain 
waking conditions, in which we. relax attention, both 
external and internal, and yield ourselves wholly to 
the spontaneous play of memory and fancy. 

It is plain at a glance that the simultaneous con- 
currence of wholly disconnected initial impulses will 
serve to impress a measure of disconnectedness on our 
dream-images. From widely remote parts of the 
organism there come impressions which excite each 
its peculiar visual or other image according as its 
local origin or its emotional tone is the more distinctly 
present to consciousness. Now it is a subjective ocular 
sensation suggesting a bouquet of lovely flowers, and 
close on its heels comes an impression from the organs 
of digestion suggesting all manner of obstacles ; and 
so our dream-fancy plunges from a vision of flowers to 
one of dreadful demons. 

Let us now look at the way in which the laws of 
association working on the incongruous elements thus 
cast up into our dream-consciousness, will serve to 
give a yet greater appearance of disorder and confusion 
to our dream-combinations. According to these laws, 



158 DKEAMP. 

any idea may, under certain circumstances, call up 
another, if the corresponding impressions have only 
once occurred together, or if the ideas have any degree 
of resemblance, or, finally, if only they stand in 
marked contrast with, one another. Any accidental 
coincidence of events, such as meeting a person at a 
particular foreign resort, and any insignificant re- 
semblance between objects, sounds, etc., may thus 
supply a path, so to speak, from fact to dream-fancy. 

In our waking states these innumerable paths of 
association are practically closed by the supreme 
energy of the coherent groups of impressions furnished 
us from the world without through our organs of sense, 
and also by the volitional control of internal thought 
in obedience to the pressure of practical needs and 
desires. In dream-life both of these influences are 
withdrawn, so that delicate threads of association, 
which have no chance of exerting their pull, so to 
speak, in our waking states, now make known their 
hidden force. Little wonder, then, that the filaments 
which, bind together these dream-successions should 
escape detection, since even in our waking thought 
we so often fail to see the connection which makes us 
pass in recollection from a name to a visible scene or 
perhaps to an emotional vibration. 

It is worth noting that the origin of an association 
is often to be looked for in one of those momentary 
half-conscious acts of waking imagination to which 
reference has already been made. A friend, for 
example, has been speaking to us of some common 
acquaintance, remarking on his poor health. The 
language calls up, vaguely, a visual representation of 



CONDITIONS OF INCOHEEENT DEEAMS 159 

the person sinking in health and dying. An associa- 
tion will thus be formed between this person and the 
idea of death. A night or two after, the image of this 
person somehow recurs to our dream-fancy, and we 
straightway dream that we are looking at his corpse, 
watching his funeral, and so on. The links of the 
chain which holds together these dream-images were 
really forged, in part, in our waking hours, though the 
process was so rapid as to escape our attention. It 
may be added, that in many cases where a juxtaposition 
of dream-images seems to have no basis in waking life, 
careful reflection will occasionally bring to light some 
actual conjunction of impressions so momentary as to 
have faded from our recollection. 

We must remember, further, how great an apparent 
disorder will invade our imaginative dream-life when 
the binding force of resemblance has unchecked play. 
In waking thought we have to connect things accord- 
ing to their essential resemblances, classifying objects 
and events for purposes of knowledge or action, accord- 
ing to their widest or their most important points of 
similarity. In sleep, on the contrary, the slightest 
touch of resemblance may engage the mind and affect 
the direction of fancy. In a sense we may be said, 
when dreaming, to discover mental affinities between 
impressions and feelings, including those subtle links 
of emotional analogy of which I have already spoken. 
This effect is well illustrated in a dream recorded by 
M. Maury, in which he passed from one set of images 
to another through some similarity of names, as that 
between corps and cor. Such a movement of fancy 
would, of course, be prevented in full waking conscious- 



1G0 DREAMS. 

ness by a predominant attention to the meaning of the 
sounds. 

It will be possible, I think, after a habit of analyz- 
ing one's dreams in the light of preceding experience 
has been formed, to discover in a good proportion of 
cases some hidden force of association which draws 
together the seemingly fortuitous concourse of our 
dream-atoms. That we should expect to do so in 
every case is unreasonable, since, owing to the number- 
less fine ramifications which belong to our familiar 
images, many of the paths of association followed by 
our dream-fancy cannot be afterwards retraced. 

To illustrate the odd way in which our images get 
tumbled together through the action of occult asso- 
ciation forces, I will record a dream of my own. I 
fancied I was at the house of a distinguished literary 
acquaintance, at her usual reception hour. I expected 
the friends I was in the habit of meeting there. 
Instead of this, I saw a number of commonly dressed 
people having tea. My hostess came up and apolo- 
gized for having asked me into this room. It was, she 
said, a tea-party which she prepared for poor people at 
sixpence a head. After puzzling over this dream, . I 
came to the conclusion that the missing link was a 
verbal one. A lady who is a connection of my 
friend, and bears the same name, assists her sister in a 
large kind of benevolent scheme. I may add that I 
had not, so far as I could recollect, had occasion very 
recently to think of this benevolent friend, but I had 
been thinking of my literary friend in connection with 
her anticipated return to town. 

In thus seeking to trace, amid the superficial chaos 



DREAM-FANCY AS CONSTRUCTIVE. 1G1 

of dream-fancy, its hidden connections, I make no 
pretence to explain why in any given case these 
particular paths of association should be followed, and 
more particularly why a slender thread of association 
should exert a pull where a stronger cord fails to do so. 
To account for this, it would be necessary to call in 
the physiological hypothesis that among the nervous 
elements connected with a particular element, a, already 
excited, some, as m and n, are at the moment, owing to 
the state of their nutrition or their surrounding in- 
fluences, more powerfully predisposed to activity than 
other elements, as b and c. 

The subject of association naturally conducts us to 
the second great problem in the theory of dreams — the 
explanation of the order in which the various images 
group themselves in all our more elaborate dreams. 

Coherence of Breams. 

A fully developed dream is a complex of many 
distinct illusory sense-presentations : in this respect it 
differs from the illusions of normal waking life, which 
are for the most part single and isolated. And this 
complex of quasi-presentations appears somehow or 
other to fall together into one whole scene or series 
of events, which, though it may be very incongruous 
and absurdly impossible from a waking point of view, 
nevertheless makes a single object for the dreamer's 
internal vision, and has a certain degree of artistic 
unity. This plastic force, which selects and binds 
together our unconnected dream-images, has frequently 
been referred to as a mysterious spiritual faculty, 
under the name of " creative fancy." Thus Cudworth 



162 DKEAMS. 

remarks, in his Treatise concerning Eternal and Im- 
mutable Morality: "That dreams are many times 
begotten by the phantastical power of the soul itself 
... is evident from the orderly connection and 
coherence of imaginations which many times are con- 
tinued in a long chain or series." One may find a good 
deal of mystical writing on the nature and activity of 
this faculty, especially in German literature. The ex- 
planation of this element of organic unity in dreams 
is, it may be safely said, the crux in the science of 
dreams. That the laws of psychology help us to 
understand the sequences of dream-images, we have 
seen. What we have now to ask is whether these laws 
throw any light on the orderly grouping of the ele- 
ments so brought up in consciousness in the form of a 
connected experience. 

It is to be remarked at the outset that a singular 
kind of unity is sometimes given to our dream-com- 
binations by a total or partial coalescence of different 
images. The conditions of such coalescence have been 
referred to already. 1 Simultaneous impressions or 
images will always tend to coalesce with a force which 
varies directly as the degree of their similarity. Some- 
times this coalescence is instantaneous and not made 
known to consciousness. Thus, Eadestock suggests 
that if the mind of the sleeper is simultaneously in- 
vaded by an unpleasant sensation arising out of some 
disturbance of the functions of the skin, and a subjec- 
tive visual sensation, the resulting mental image may 
be a combination of the two, under the form of a 
caterpillar creeping over the bodily surface. And the 
1 See p. 53. 






TRANSFORMATION OF IMAGES. 163 

coalescence may even be prepared by sub-conscious 
operations of waking imagination. Thus, for example, 
I once spoke about the cheapness of hares to a member 
of my family, who somewhat grimly suggested that they 
were London cats. I did not dwell on the idea, but 
the following night I dreamt that I saw a big hybrid 
creature, half hare, half cat, sniffing about a cottage. 
As it stood on its hind legs and took a piece of food 
from a window-ledge, I became sure that it was a cat. 
Here it is plain that the cynical observation of my 
relative had, at the moment, partially excited an image 
of this feline hare. In some dreams, again, we may 
become aware of the process of coalescence, as when 
persons who at one moment were seen to be distinct 
appear to our dream-fancy to run together in some 
third person. 

A very similar kind of unification takes place be- 
tween sequent images under the form of transformation. 
When two images follow one another closely, and have 
anything in common, they readily assume the form of a 
transmutation. There is a sort of overlapping of the 
mental images, and so an appearance of continuity pro- 
duced in some respects analogous to that which arises 
in the wheel-of-life (thaumatrope) class of sense-illusions. 
This would seem to account for the odd transformations 
of personality which not unfrequently occur in dreams, 
in which a person appears, by a kind of metempsychosis, 
to transfer his physical ego to another, and in which the 
dreamer's own bodily phantom plays similar freaks. 
And the same principle probably explains those dis- 
solving-view effects which are so familiar an accom- 
paniment of dream-scenery. 1 

1 See Maury, loo. cit., p. 146. 



164 DREAMS. 

But passing from this exceptional kind of unity in 
dreams, let us inquire how the heterogeneous elements 
of our dream-fancy become ordered and arranged when 
they preserve their separate existence. If we look 
closely at the structure of our more finished dreams, we 
find that the appearance of harmony, connectedness, or 
order, may be given in one of two ways. There may, 
first of all, be a subjective harmony, the various images 
being held together by an emotional thread. Or there 
may, secondly, be an objective harmony, the parts of 
the dream, though answering to no particular experi- 
ences of waking life, bearing a certain resemblance to 
our habitual modes of experience. Let us inquire into 
the way in which each kind of order is brought about. 

Lyrical Element in Dreams. 

The only unity that belongs to many of our dreams 
is a subjective emotional unity. This is the basis of 
harmony in lyrical poetry, where the succession of 
images turns mainly on their emotional colouring. 
Thus, the images that float before the mind of the Poet 
Laureate, in his In Memoriam, clearly have their link 
of connection in their common emotional tone, rather 
than in any logical continuity. Dreaming has been 
likened to poetic composition, and certainly many of 
our dreams are built upon a groundwork of lyrical 
feeling. They might be marked off, perhaps, as our 
lyrical dreams. 

The way in which this emotional force acts in 
these cases has already been hinted at. We have seen 
that the analogy of feeling is a common link between 
dream-images. Now, if any shade of feeling becomes 



DREAM- STRUCTURE AND FEELING. 165 

fixed and dominant in the mind, it will tend to control 
all the images of the time, allowing certain congruous 
ones to enter, and excluding others. 1 If, for example, 
a feeling of distress occupies the mind, distressing 
images will have the advantage in the struggle for 
existence which goes on in the world of mind as well 
as in that of matter. We may say that attention, 
which is here wholly a passive process, is controlled by 
the emotion of the time, and bent in the direction of 
congruent or harmonious images. 

Now, a ground-tone of feeling of a certain com- 
plexion, answering to the sum of sensations arising in 
connection with the different organic processes of the 
time, is a very frequent foundation of our dream- 
structure. So frequent is it, indeed, that one might 
almost say there is no dream in which it is not one 
great determining factor. The analysis of a very large 
number of dreams has convinced me that traces of this 
influence are discoverable in a great majority. 

I will give a simple illustration of this lyrical type 
of dream. A little girl of about four years and three- 
quarters went with her parents to Switzerland. On 
their way she was taken to the cathedral at Strasburg, 
and saw the celebrated clock strike, and the figures of 
the Apostles come out, etc. In Switzerland she stayed 
at Gimmelwald, near Miirren, opposite a fine mass of 
snowy mountains. One morning she told her father 
that she had had " such a lovely dream." She fancied 
she was on the snow-peaks with her nurse, and walked 
on to the sky. There came out of the sky " such 

1 See what was said respecting the influence of a dominant 
emotional agitation on the interpretation of actual sense-impressions. 



166 DREAMS. 

beautiful things," just like the figures of the clock. 
This vision of celestial things was clearly due to the 
fact that both the clock and the snow-peaks touching 
the blue sky had powerfully excited her imagination, 
filling her with much the same kind of emotion, 
namely, wonder, admiration, and longing to reach an 
inaccessible height. 

Our feelings commonly have a gradual rise and 
fall, and the organic sensations which so often con- 
stitute the emotional basis of our lyrical dreams 
generally have stages of increasing intensity. More- 
over, such a persistent ground-feeling becomes rein- 
forced by the images which it sustains in consciousness. 
Hence a certain crescendo character in our emotional 
dreams, or a gradual rise to some culminating point or 
climax. 

This phase of dream can be illustrated from the 
experience of the same little girl. When just five 
years old, she was staying at Hampstead, near a church 
which struck the hours somewhat loudly. One morn- 
ing she related the following dream to her father (I 
use her own language). The biggest bells in the world 
were ringing ; when this was over the earth and houses 
began to tumble to pieces; all the seas, rivers, and ponds 
flowed together, and covered all the land with black 
water, as deep as in the sea where the ships sail; 
people were drowned ; she herself flew above the 
water, rising and falling, fearing to fall in ; she then 
saw her mamma drowned, and at last flew home to tell 
her papa. The gradual increase of alarm and distress 
expressed in this dream, having its probable cause in 
the cumulative effect of the disturbing sound of the 
church bells, must be patent to all. 



EXAMPLES OF LYRICAL DREAMS. 167 

The following rather comical dream illustrates quite 
as clearly the growth of a feeling of irritation and 
vexation, probably connected with the development of 
some slightly discomposing organic sensation. I dreamt 
I was unexpectedly called on to lecture to a class of 
young women, on Herder. I began hesitatingly, with 
some vague generalities about the Augustan age of 
German literature, referring to the three well-known 
names of Lessing, Schiller, and Goethe. Immediately 
my sister, who suddenly appeared in the class, took me 
up, and said she thought there was a fourth distin- 
guished name belonging to this period. I was annoyed 
at the interruption, but said, with a feeling of triumph, 
" I suppose you mean Wieland ? " and then appealed to 
the class whether there were not twenty persons who 
knew the names I had mentioned to one who knew Wie- 
land's name. Then the class became generally dis- 
orderly. My feeling of embarrassment gained in depth. 
Finally, as a climax, several quite young girls, about 
ten years and less, came and joined the class. The 
dream broke off abruptly as I w r as in the act of taking 
these children to the wife of an old college tutor, to 
protest against their admission. 

It is worth noting, perhaps, that in this evolution 
of feeling in dreaming the quality of the emotion 
may vary within certain limits. One shade of feeling 
may be followed by another and kindred shade, so 
that the whole dream still preserves a degree, though 
a less obvious degree, of emotional unity. Thus, for 
example, a lady friend of mine once dreamt that she 
was in church, listening to a well-known novelist of 
the more earnest sort, preaching. A wounded soldier 



168 DKEAMS. 

was brought in to be shot, because he was mortally 
wounded, and had distinguished himself by his bravery. 
He was then shot, but not killed, and, rolling over in 
agony, exclaimed, " How long ! " The development 
of an extreme emotion of horror out of the vague 
feeling of awe which is associated with a church, gives 
a curious interest to this dream. 

Verisimilitude in Dreams. 

I must not dwell longer on this emotional basis 
of dreams, but pass to the consideration of the second 
and objective kind of unity which characterizes many 
of our more elaborate dream-performances. In spite 
of all that is fitful and grotesque in dream-combi- 
nation, it still preserves a distant resemblance to our 
actual experience. Though no dream reproduces a 
particular incident or chain of incidents in this ex- 
perience, though the dream-fancy invariably trans- 
forms the particular objects, relations, and events of 
wakiDg life, it still makes the order of our daily 
experience its prototype. It fashions its imaginary 
world on the model of the real. Thus, objects group 
themselves in space, and act on one another conform- 
ably to these perceived space-relations ; events succeed 
one another in time, and are often seen to be connected ; 
men act from more or less intelligible motives, and 
so on. In this way, though the dream-fancy sets at 
nought the particular relations of our experience, it 
respects the general and constant relations. How are 
we to account for this ? 

It is said by certain philosophers that this super- 
position of the relations of space, time, causation, 



■<?-&*.. ^^^^^^^H 



RATIONAL CONGRUITY IN DREAMS. 169 

etc., on the products of our drearn-fancy is due to the 
fact that all experience arises by a synthesis of mental 
forms with the chaotic matter of sense-impressions. 
These philosophers allow, however, that all particular 
connections are determined by experience. Accord- 
ingly, what we have to do here is to inquire how far 
this scientific method of explaining mental connec- 
tions by facts of experience will carry us. In other 
words, we have to ask what light can be thrown on 
these tendencies of dream-imagination by ascertained 
psychological laws, and more particularly by what are 
known as the laws of association. 

These laws tell us that of two mental phenomena 
which occur together, each will tend to recall the 
other whenever it happens to be revived. On the 
physiological side, this means that any two parts of 
the nervous structures which have acted together 
become in some way connected, so that when one 
part begins to work the other will tend to work also. 
But it is highly probable that a particular structure 
acts in a great many different ways. Thus, it may be 
stimulated by unlike modes of stimuli, or it may enter 
into very various connections with other structures. 
What will follow from this ? One consequence would 
appear to be that there will be developed an organic 
connection between the two structures, of such a kind 
that whenever one is excited the other will be disposed 
to act somehow and anyhow, even when there is nothing 
in the present mode of activity of the first structure to 
determine the second to act in some one definite way, 
in other words, when this mode of activity is, roughly- 
speaking, novel. 



170 DREAMS. 

Let me illustrate this effect in one of the simplest 
cases, that of the visual organ. If, when walking 
out on a daik night, a few points in my retina are 
suddenly stimulated by rays of light, and I recognize 
some luminous object in a corresponding direction, I 
am prepared to see something above and below, to the 
right and to the left of this object. Why is this? 
There may from the first have been a kind of innate 
understanding among contiguous optic fibres, predis- 
posing them to such concerted action. But however 
this be, this disposition would seem to have been 
largely promoted by the fact that, throughout my 
experience, the stimulation of any retinal point has 
been connected with that of adjoining points, either 
simultaneously by some second object, or successively 
by the same object as the eye moves over it, or as 
the object itself moves across the field of vision. 

When, therefore, in sleep any part of the optic 
centres is excited in a particular way, and the images 
thus arising have their corresponding loci in space 
assigned to them, there will be a disposition to refer 
any other visual images which happen at the moment 
to arise in consciousness to adjacent parts of space. 
The character of these other images will be determined 
by other special conditions of the moment; their locality 
or position in space will be determined by this organic 
connection. We may, perhaps, eall these tendencies 
to concerted action of some kind general associative 
dispositions. 

Just as there are such dispositions to united action 
among various parts of one organ of sense, so there 
may be among different organs, which are either con- 






I V> ^' 'JBii ■ 3i'i£.,4ttife4«Ji*'^fc''. t X 



HH 



ASSOCIATIVE DISPOSITIONS. 17J 

nected originally in the infant organism, or have 
communications opened up by frequent coexcitation 
of the two. Such links there certainly are between 
the organs of taste and smell, and between the ear and 
the muscular system in general, and more particu- 
larly the vocal organ. 1 A new odour often sets us 
asking how the object would taste, and a series of 
sounds commonly disposes us to movement of some 
kind or another. How far there may be finer threads 
of connection between other organs, such as the eye 
and the ear, which do not betray themselves amid the 
stronger forces of waking mental life, one cannot say. 
Whatever their number, it is plain that they will 
exert their influence within the comparatively narrow 
limits of dream-life, serving to impress a certain cha- 
racter on the images which happen to be called up 
by special circumstances, and giving to the combina- 
tion a slight measure of congruity. Thus, if I were 
dreaming that I heard some lively music, and at the 
same time an image of a friend was anyhow excited, 
my dream-fancy might not improbably represent this 
person as performing a sequence of rhythmic move- 
ments, such as those of riding, dancing, etc. 

A narrower field for these general associative dis- 
positions may be found in the tendency, on the recep- 
tion of an impression of a given character, to look for 
a certain kind of second impression ; though the exact 
nature of this is unknown. Thus, for example, the 

1 It is proved experimentally that the ear has a much closer 
organic connection with the vocal organ than the eye has. Donders 
found tliat the period required for responding vocally to a sound- 
signal is less than that required for responding in the same way to a 
light-signal. 



172 DREAMS. 

form and colour of a new flower suggest a scent, and 
the perception of a human form is accompanied by a 
vague representation of vocal utterances. These general 
tendencies of association appear to me to be most 
potent influences in our dream-life. The many strange 
human forms which float before our dream-fancy are 
apt to talk, move, and behave like men and women in 
general, however little they resemble their actual pro- 
totypes, and however little individual consistency of 
character is preserved by each of them. Special con- 
ditions determine what they shall say or 'do ; the 
general associative disposition accounts for their saying 
or doing something. 

We thus seem to find in the purely passive pro- 
cesses of association some ground for that degree of 
natural coherence and rational order which our more 
mature dreams commonly possess. These processes go 
far to explain, too, that odd mixture of rationality 
with improbability, of natural order and incongruity, 
which characterizes our dream-combinations. 

Rational Construction in Dreams. 

Nevertheless, I quite agree with Herr Volkelt that 
association, even in the most extended meaning, cannot 
explain all in the shaping of our dream- pictures. The 
" phantastical power " which Cud worth talks about 
clearly includes something besides. It is an erroneous 
supposition that when we are dreaming there is a com- 
plete suspension of the voluntary powers, and conse- 
quently an absence of all direction of the intellectual 
processes. This supposition, which has been maintained 
by numerous writers, from Dugald Stewart downwards, 



*r.Mi\* rf'fifcji.; *•.**.« * 



VOLUNTARY ATTENTION IN DREAMS. 173 

seems to be based on the fact that we frequently find 
ourselves in dreams striving in vain to move the whole 
body or a limb. But this only shows, as M. Maury 
remarks in the work already referred to, that our 
volitions are frustrated through the inertia of our 
bodily organs, not that these volitions do not take 
place. In point of fact, the dreamer, not to speak of 
the somnambulist, is often conscious of voluntarily going 
through a series of actions. This exercise of volition 
is shown unmistakably in the well-known instances of 
extraordinary intellectual achievements in dreams, as 
Condillac's composition of a part of his Cours d' Etudes. 
No one would maintain that a result of this kind was 
possible in the total absence of intellectual action 
carefully directed by the will. And something of this 
same control shows itself in all our more fully de- 
veloped dreams. 

One manifestation of this voluntary activity in 
sleep is to be found in those efforts of attention which 
not unfrequently occur. I have remarked that, speak- 
ing roughly and in relation to the waking condition, 
the state of sleep is marked by a subjection of the 
powers of attention to the force of the mental images 
present to consciousness. Yet something resembling 
an exercise of voluntary attention sometimes happens 
in sleep. The intellectual feats just spoken of, unless, 
indeed, they are referred to some mysterious uncon- 
scious mental operations, clearly involve a measure of 
volitional guidance. All who dream frequently are 
occasionally aware on awaking of having greatly exer- 
cised their attention on the images presented to them 
during sleep. I myself am often able to recall an 



174 DREAMS. 

effort to see beautiful objects, which threatened to dis- 
appear from my field of vision, or to catch faint receding 
tones of preternatural sweetness; and some dreamers 
allege that -they are able to retain a recollection of the 
feeling of strain connected with such exercise of atten- 
tion in sleep. 

The main function of this voluntary attention in 
dream-life is seen in the selection of those images 
which are to pass the threshold of clear consciousness. 
I have already spoken of a selective action brought 
about by the ruling emotion. In this case, the atten- 
tion is held captive by the particular feeling of the 
moment. Also a selective process goes on in the case 
of the action of those associative dispositions just re- 
ferred to. But in each of these cases the action of 
selective attention is comparatively involuntary, passive, 
and even unconscious, not having anything of the 
character of a conscious striving to compass some end. 
Besides this comparatively passive play of selective 
attention, there is an active play, in which there is 
a conscious wish to gain an end ; in other words, the 
operation of a definite motive. This motive may be 
described as an intellectual impulse to connect and 
harmonize what is present to the mind. The voluntary 
kind of selection includes and transcends each of 
the involuntary kinds. It has as its result an imitation 
of that order which is brought about by what I have 
called the associative dispositions, only it consciously 
aims at this result. And it is a process controlled by a 
feeling, namely, the intellectual sentiment of consis- 
tency, which is not a mode of emotional excitement 
enthralling the will, but a calm motive, guiding the 



^H -m,*.' -a-«Xj.', ^ivL-j 



IMPULSE TO LOOK FOR ORDER. 175 

activities of attention. It thus bears somewhat the same 
relation to the emotional selection already spoken of, 
as dramatic creation bears to lyrical composition. 

This process of striving to seize some connecting 
link, or thread of order, is illustrated whenever, in 
waking life, we are suddenly brought face to face with 
an unfamiliar scene. When taken into a factory, we 
strive to arrange the bewildering chaos of visual im- 
pressions under some scheme, by help of which we are 
said to understand the scene. So, if on entering a 
room we are plunged in medias res of a lively conver- 
sation, we strive to find a clue to the discussion. When- 
ever the meaning of a scene is not at once clear, and 
especially whenever there is an appearance of confusion 
in it, we are conscious of a painful feeling of per- 
plexity, which acts as a strong motive to ever-renewed 
attention. 1 

In touching on this intellectual impulse to connect 
the disconnected, we are, it is plain, approaching the 
question of the very foundations of our intellectual 
structure. That there is this impulse firmly rooted in 
the mature mind nobody can doubt ; and that it 
manifests itself in early life in the child's recurring 
" Why ? " is equally clear. But how we are to account 
for it, whether it is to be viewed as a mere result of 
the play of associated fragments of experience, or as 
something involved in the very process of the associa- 
tion of ideas itself, is a question into which I cannot 
here enter. 

1 On the nature of this impulse, as illustrated in waking and in 
sleep, see the article by Delbceuf, " Le Sommeil et Ins Reves," in the 
Revue PhilosopJiique, June, 18S0, p. 636. 



176 DEEAMS. 

What I am here concerned to show is that the 
search for consistency and connection in the manifold 
impressions of the moment is a deeply rooted habit of 
the mind, and one which is retained in a measure 
during sleep. When, in this state, our minds are in- 
vaded by a motley crowd of unrelated images, there 
results a disagreeable sense of confusion ; and this feeling 
acts as a motive to the attention to sift out those pro- 
ducts of the dream- fancy which may be made to cohere. 
When once the foundations of a dream-action are laid, 
new images must to some extent fit in with this ; and 
here there is room for the exercise of a distinct impulse 
to order the chaotic elements of dream-fancy in certain 
forms. The perception of any possible relation between 
one of the crowd of new images ever surging above the 
level of obscure consciousness, and the old group at 
once serves to detain it. The concentration of atten- 
tion on it, in obedience to this impulse to seek for an 
intelligible order, at once intensifies it and fixes it, 
incorporating it into the series of dream-pictures. 

Here is a dream which appears to illustrate this 
impulse to seek an intelligible order in the confused 
and disorderly. After being occupied with correcting 
the proofs of my volume on Pessimism, I dreamt that 
my book was handed to me by my publisher, fully 
illustrated with coloured pictures. The frontispiece 
represented the fantastic figure of a man gesticulating 
in front of a ship, from which he appeared to have just 
stepped. My publisher told me it was meant for Hamlet, 
and I immediately reflected that this character had been 
selected as a concrete example of the pessimistic ten- 
dency. I may add that, on awaking, I was distinctly 



•£*...• ^i «.". '•» -it.i" Jt'-&i . H H ,v I • 



EXAMPLES OF IMPULSE TO AKKANGE. 177 

aware of having felt puzzled when dreaming, and of 
having striven to read a meaning into the dream. 

The rationale of this dream seems to me to be 
somewhat as follows. The image of the completed 
volume represented, of course, a recurring anticipatory 
image of waking life. The coloured plates were due 
probably to subjective optical sensations simultaneously 
excited, which were made to fit in (with or without an 
effort of voluntary attention) with the image of the 
book under the form of illustrations. But this stage 
of coherency did not satisfy the mind, which, still 
partly confused by the incongruity of coloured plates 
in a philosophic work, looked for a closer connection. 
The image of Hamlet was naturally suggested in con- 
nection with pessimism. The effort to discover a 
meaning in the pictures led to the fusion of this image 
with one of the subjective spectra, and in this way the 
idea of a Hamlet frontispiece probably arose. 

The whole process of dream-construction is clearly 
illustrated in a curious dream recorded by Professor 
Wundt. 1 Before the house is a funeral procession : it 
is the burial of a friend, who has in reality been dead 
for some time past. The wife of the deceased bids 
him and an acquaintance who happens to be with him 
go to the other side of the street and join the proces- 
sion. After she has gone away, his companion remarks 
to him, " She only said that because the cholera rages 
over yonder, and she wants to keep this side of the 
street to herself." Then comes an attempt to flee from 
the region of the cholera. Eeturning to his house, he 
finds the procession gone, but the street strewn with 

1 Fhysiclogisclie Psychologie, p. 6G0. 



178 DREAMS. 

rich nosegays ; and he further observes crowds of men 
who seem to be funeral attendants, and who, like him- 
self, are hastening to join the procession. These are, 
oddly enough, dressed in red. When hurrying on, it 
occurs to him that he has forgotten to take a wreath 
for the coffin. Then he wakes up with beating of the 
heart. 

The sources of this dream are, according to Wundt, 
as follows. First of all, he had, on the previous da} r , 
met the funeral procession of an acquaintance. Again, 
lie had read of cholera breaking out in a certain town. 
Once more, he had talked about the particular lady 
with this friend, who had narrated facts which clearly 
proved her selfishness. The hastening to flee from 
the infected neighbourhood and to overtake the 
procession was prompted by the sensation of heart- 
beating. Finally, the crowd of red bier-followers, and 
the profusion of nosegays, owed their origin to subjec- 
tive visual sensations, the " light-chaos " which often 
appears in the dark. 

Let us now see for a moment how these various 
elements may have become fused into a connected chain 
of events. First of all, it is clear that this dream is 
built up on a foundation of a gloomy tone of feeling, 
arising, as it would seem, from an irregularity of the 
heart's action. Secondly, it owes its special structure 
and its air of a connected sequence of events, to those 
tendencies, passive and active, to order the chaotic of 
which I have been speaking. Let us try to trace this 
out in detail. 

To begin with, we may suppose that the image of the 
procession occupies the dreamer's mind. From quite 



'wL-y?' .ilitA * ,4u*J,A£lS£a 



A DREAM ANALYZED. 179 

another source the image of the lady enters conscious- 
ness, bringing with it that of her deceased husband and 
of the friend who has recently been talking about her. 
These new elements adapt themselves to the scene, 
partly by the passive mechanism of associative dispo- 
sitions, and partly, perhaps, by the activity of voluntary 
selection. Thus, the idea of the lady's husband would 
naturally recall the fact of his death, and this would fall 
in with the pre-existing scene under the form of the 
idea that he is the person who is now being buried. 
The next step is very interesting. The image of the 
lady is associated with the idea of selfish motives. 
This would tend to suggest a variety of actions, but the 
one which becomes a factor of the dream is that which 
is specially adapted to the pre-existing representations, 
namely, of the procession on the further side of the 
street, and the cholera (which last, like the image of 
the funeral, is, we may suppose, due to an independent 
central excitation). That is to say, the request of the 
lady, and its interpretation, are a resultant of a number 
of adaptative or assimilative actions, under the sway 
of a strong desire to connect the disconnected, and a 
lively activity of attention. Once more, the feeling 
of oppression of the heart, and the subjective stimu- 
lation of the optic nerve, might suggest numberless 
images besides those of anxious flight and of red-clad 
men and nosegays ; they suggest these, and not others, 
in this particular case, because of the co-operation of 
the impulse of consistency, which, setting out with the 
pre-existing mental images, selects from among many 
tendencies of reproduction those which happen to 
chime in with the #cene. 



180 DKEAM8. 

TJie Nature of Dream-Intelligence. 

It must not be supposed that this process of welding 
together the chaotic materials of our dreams is ever 
carried out with anything like the clear rational pur- 
pose of which we are conscious when seeking, in 
waking life, to comprehend some bewildering spectacle. 
At best it is a vague longing, and this longing, it may 
be added, is soon satisfied. There is, indeed, something 
almost pathetic in the facility with which the dreamer's 
mind can be pacified with the least appearance of a 
connection. Just as a child's importunate " Why ? " 
is often silenced by a ridiculous caricature of an ex- 
planation, so the dreamer's intelligence is freed from 
its distress by the least semblance of a uniting order. 

It thus remains true with respect even to our most 
coherent dreams, that there is a complete suspension, 
or at least a considerable retardation, of the highest 
operations of judgment and thought; also a great 
enfeeblement, to say the least of it, of those sentiments 
such as the feeling of consistency and the sense of the 
absurd which are so intimately connected with these 
higher intellectual operations. 

In order to illustrate how oddly our seemingly 
rational dreams caricature the operations of waking- 
thought, I may, perhaps, be allowed to record two of 
my own dreams, of which I took careful note at the 
time. 

On the first occasion I went " in my dream " to 
the " Stores " in August, and found the place empty. 
A shopman brought me some large fowls. I asked 
their price, and he answered, " Tenpence a pound." I 



LIMITS OF DEEAM-INTELLIGENCE. 181 

then asked their weight, so as to get an idea of their 
total cost, and he replied, " Forty pounds." Not in 
the least surprised, I proceeded to calculate their cost : 
40 x 10 = 400 ~ 12 = 33J. But, oddly enough, I 
took this quotient as pence, just as though I had not 
already divided by 12, and so made the cost of a fowl 
to he 2s. 9d., which seemed to me a fair enough price. 

In my second dream I was at Cambridge, among a 
lot of undergraduates. I saw a coach drive up with 
six horses. Three undergraduates got out of the coach. 
I asked them why they had so many horses, and they 
said, " Because of the luggage." I then said, " The 
luggage is much more than the undergraduates. Can 
you tell me how to express this in mathematical sym- 
bols ? This is the way : if x is the weight of an 
undergraduate, then x + x n represents the weight of 
an undergraduate and his luggage together." I noticed 
that this sally was received with evident enjoyment. 1 

We may say, then, that the structure of our dreams, 
equally with the fact of their completely illusory 
character, points to the conclusion that during sleep, 
just as in the moments of illusion in waking life, there 

J I may, perhaps, observe, after giving two dreams -which have to do 
with mathematical operations, that, though I was very fond of them in 
my college days, I have long ceased to occupy myself with these pro- 
cesses. I would add, by way of redeeming my dream-intelligence from 
a deserved charge of silliness, that I once performed a respectable in- 
tellectual feat when asleep. I put together the riddle, " What might 
a wooden ship say when her side was stove in? Tremendous!" 
(Tree-mend-us). I was aware of having tried to improve on the form 
of this pun. I am happy to say I am not given to punning during 
waking life, though I had a fit of it once. It strikes me that punning, 
consisting as it does essentially of overlooking sense and attending to 
sound, is just such a debased kind of intellectual activity as one might 
look for in sleep. 



182 DREAMS. 

is a deterioration of our intellectual life. The highest 
intellectual activities answering to the least stable 
nervous connections are impeded, and what of intellect 
remains corresponds to the most deeply organized 
connections. 

In this way, our dream-life touches that childish 
condition of the intelligence which marks the decadence 
of old age and the encroachments of mental disease. 
The parallelism between dreams and insanity has been 
pointed out by most writers on the subject. Kant 
observed that the madman is a dreamer awake, and 
more recently Wundt has remarked that, when asleep, 
we " can experience nearly all the phenomena which 
meet us in lunatic asylums." The grotesqueness of the 
combinations, the lack of all judgment as to consistency, 
fitness, and probability, are common characteristics 
of the short night- dream of the healthy and the long 
day-dream of the insane. 1 

But one great difference marks off the two domains. 
When dreaming, we are still sane, and shall soon prove 
our sanity. After all, the dream of the sleeper is cor- 
rected, if not so rapidly as the illusion of the healthy 
waker. As soon as the familiar stimuli of light and 
sound set the peripheral sense-organs in activity, and 
call back the nervous system to its complete round of 
healthy action, the illusion disappears, and we smile at 
our alarms and agonies, saying, " Behold, it was a 
dream ! " 

On the practical side, the illusions and hallucina- 
tions of sleep must be regarded as comparatively harni- 

1 See Eadestock, op. eit., ch. ix. ; Vergleichung des Traumes mil dem 
Wdhminn. 



•O'v'.tfw.. .rV'4it:<"is*»livV.: 1 tiA i '' 



KS 



DKEAM-LIFE AND INSANITY. 183 

less. The sleeper, in healthy conditions of sleep, 
ceases to be an agent, and the illusions which enthral 
his brain have no evil practical consequences. They 
may, no doubt, as we shall see in a future chapter, 
occasionally lead to a subsequent confusion of fiction 
and reality in waking recollection. But with the 
exception of this, their worst effect is probably the 
lingering sense of discomfort which a " nasty dream " 
sometimes leaves with us, though this may be balanced 
by the reverberations of happy dream-emotions which 
sometimes follow us through the day. And however 
this be, it is plain that any disadvantages thus arising 
are more than made good by the consideration that 
our liability to these nocturnal illusions is connected 
with the need of that periodic recuperation of the 
higher nervous structures which is a prime condition 
of a vigorous intellectual activity, and so of a triumph 
over illusion during waking life. 

For these reasons dreams may properly be classed 
with the illusions of normal or healthy life, rather than 
with those of disease. They certainly lie nearer this 
region than the very similar illusions of the somnam- 
bulist, which with respect to their origin appear to be 
more distinctly connected with a pathological con- 
dition of the nervous system, and which with respect 
to their practical consequences may easily prove so 
disastrous. 

After-Dreams. 

In concluding this account of dreams, I would call 
attention to the importance of the transition states 
between sleeping and waking, in relation to the pro- 



184 DREAMS. 

cluction of sense-illusion. And this point may le 
touched on here all the more appropriately, since it 
helps to bring out the close relation between waking 
and sleeping illusion. The mind does not pass sud- 
denly and at a bound from the condition of dream- 
fancy to that of waking perception. I have already 
had occasion to touch on the " hypnagogic state," that 
condition of somnolence or " sleepiness " in which ex- 
ternal impressions cease to act, the internal attention 
is relaxed, and the weird imagery of sleep begins to 
unfold itself. And just as there is this anticipation of 
dream-hallucination in the presomnial condition, so 
there is the survival of it in the postsomnial condition. 
As I have observed, dreams sometimes leave behind 
them, for an appreciable interval after waking, a vivid 
after-impression, and in some cases even the semblance 
of a sense-perception. 

If one reflects how many ghosts and other mi- 
raculous apparitions are seen at night, and when the 
mind is in a more or less somnolent condition, the 
idea is forcibly suggested that a good proportion of 
these visions are the debris of dreams. In some cases, 
indeed, as that of Spinoza, already referred to, the hal- 
lucination (in Spinoza's case that of " a scurvy black 
Brazilian ") is recognized by the subject himself as a 
dream-image. 1 I am indebted to Mr. W. H. Pollock 
for a fact which curiously illustrates the position here 
adopted. A lady was staying at a country house. 
During the night and immediately on waking up she 

1 For Spinoza's experience, given in his own words, see Mr. F. 
Pollock's Spinoza, p. 57 ; cf. what Wundt says on his experience, Phy- 
siologische Peychologie, p. 618, footnote 2. 



t|kg«yj£Hn|Hm|fi|M|y£mura* 



AFTEE-DEEAMS AND SEECTEES. 185 

had an apparition of a strange-looking man in 
mediaeval costume, a figure by no means agreeable, 
and which seemed altogether unfamiliar to her. The 
next morning, on rising, she recognized the original of 
her hallucinatory image in a portrait hanging on the 
wall of her bedroom, which must have impressed itself 
on her brain before the occurrence of the apparition, 
though she had not attended to it. Oddly enough, she 
now learnt for the first time that the house at which 
she was staying had the reputation of being haunted, 
and by the very same somewhat repulsive-looking medi- 
aeval personage that had troubled her inter-somnolent 
moments. The case seems to me to be typical with 
respect to the genesis of ghosts, and of the reputation 
of haunted houses. 



NOTE. 

THE HYPNOTIC CONDITION. 



I have not in this chapter discussed the relation 
of dreaming to hypnotism, or the state of artificially 
produced quasi-slee.p, because the nature of this last 
is still but very imperfectly understood. In this 
condition, which is induced in a number of ways by 
keeping the attention fixed on some non-exciting ob- 
ject, and by weak continuous and monotonous stimu- 
lation, as stroking the skin, the patient can be made 
to act conformably to the verbal or other suggestion of 
the operator, or to the bodily position which he is made 
to assume. Thus, for example, if a glass containing 



186 DREAMS. 

ink is given to him, with the command to drink, he 
proceeds to drink. If his hands are folded, he proceeds 
to act as if he were in church, and so on. 

Braid, the writer who did so much to get at the 
facts of hypnotism, and Dr. Carpenter who has helped 
to make known Braid's careful researches, regard the 
actions of the hypnotized subject as analogous to ideo - 
motor movements ; that is to say, the movements due 
to the tendency of an idea to act itself out apart from 
volition. On the other hand, one of the latest in- 
quirers into the subject, Professor Heidenhain, of 
Breslau, appears to regard these actions as the outcome 
of " unconscious perceptions " (Animal Magnetism, Eng- 
lish translation, p. 43, etc.). 

In the absence of certain knowledge, it seems 
allowable to argue from the analogy of natural sleep 
that the actions of the hypnotized patient are accom- 
panied with the lower forms of consciousness, includ- 
ing sensation and perception, and that they involve 
dream-like hallucinations respecting the external 
circumstances of the moment. Begarding them in this 
light, the points of resemblance between hypnotism 
and dreaming are numerous and striking. Thus, Dr. 
Heidenhain tells us that the threshold or liminal 
value of stimulation is lowered just as in ordinary 
sleep sense-activity as a whole is lowered. According 
to Professor Weinhold, the hypnotic condition begins 
in a gradual loss of taste, touch, and the sense of tem- 
perature ; then sight is gradually impaired, while hear- 
ing remains throughout the least interfered with. 1 In 

1 See an interesting account of" Recent Researches on Hypnotism," 
by G. Stanley Hall, in Mind, January, 1881. 



THE HYPNOTIC CONDITION. 187 

this way, the mind of the patient is largely cut off from 
the external world, as in sleep, and the power of orien- 
tation is lost. Moreover, there are all the conditions 
present, both positive and negative, for the hallucina- 
tory transformation of mental images into percepts just 
as in natural sleep. Thus, the higher centres connected 
with the operations of reflection and reasoning are 
thrown hors de combat or, as Dr. Heidenhain has it, 
" inhibited." 

The condition of hypnotism is marked off from 
that of natural sleep, first of all, by the fact that the 
accompanying hallucinations are wholly due to ex- 
ternal suggestion (including the effects of bodily 
posture). Dreams may, as we have seen, be very 
faintly modified by external influences, but during 
sleep there is nothing answering to the perfect control 
which the operator exercises over the hypnotized 
subject. The largest quantity of our "dream-stuff" 
comes, as we have seen, from within and not from 
without the organism. And this fact accounts for the 
chief characteristic difference between the natural and 
the hypnotic dream. The former is complex, consist- 
ing of crowds of images, and continually changing: 
the latter is simple, limited, and persistent. As Braid 
remarks, the peculiarity of hypnotism is that the 
attention is concentrated on a remarkably narrow field 
of mental images and ideas. So long as a particular 
bodily posture is assumed, so long does the corresponding 
illusion endure. One result of this, in connection with 
that impairing of sensibility already referred to, is the 
scope for a curious overriding of sense-impressions by 
the dominant illusory percept, a process that we have 



188 DREAMS. 

seen illustrated in the active sense-illusions of waking 
life. Thus, if salt water is tasted and the patient is 
told that it is beer, he complains that it is sour. 

In being thus in a certain rapport, though so 
limited and unintelligent a rapport, with the ex- 
ternal world, the mind of the hypnotized patient 
would appear to be nearer the condition of waking 
illusion than is the mind of the dreamer. It must 
be remembered, however, and this is the second 
point of difference between dreaming and hypnotism, 
that the hypnotized subject tends to act out his hal- 
lucinations. His quasi-percepts are wont to trans- 
form themselves into actions with a degree of force 
of which we see no traces in ordinary sleep. Why 
there should be this greater activity of the motor 
organs in the one condition than in the other, seems 
to be a point as yet unexplained. All sense-im- 
pressions and percepts are doubtless accompanied by 
some degree of impulse to movement, though, for some 
reason or another, in natural and healthy sleep these 
impulses are restricted to the stage of faint nascent 
stirrings of motor activity which hardly betray them- 
selves externally. This difference, involving a great 
difference in the possible practical consequences of the 
two conditions of natural and hypnotic sleep, clearly 
serves to bring the latter condition nearer to that of 
insanity than the former condition is brought. A strong 
susceptibility to the hypnotic influence, such as 
Dr. Heidenhain describes, might, indeed, easily prove 
a very serious want of "adaptation of internal to 
external relations," whereas a tendency to dreaming 
would hardly prove a maladaptation at all. 



CHAPTER VIIL 

ILLUSIONS OF INTROSPECTION. 

We have now, perhaps, sufficiently reviewed sense- 
illusions, both of waking life and of sleep. And having 
roughly classified them according to their structure and 
origin, we are ready to go forwards and inquire whether 
the theory thus reached can be applied to other forms 
of illusory error. And here we are compelled to inquire 
at the outset if anything analogous to sense-illusion 
is to be found in that other great region of presentative 
cognition usually marked off from external perception 
as internal perception, self-reflection, or introspection. 

Illusions of Introspection defined. 

This inquiry naturally sets out with the question : 
What is meant by introspection ? This cannot be 
better defined, perhaps, than by saying that it is the 
mind's immediate reflective cognition of its own states 
as such. 

In one sense, of course, everything we know may 
be called a mental state, actual or imagined. Thus, a 
sense-impression is known, exactly like any other feeling 
of the mind, as a mental phenomenon or mental modifl- 



190 ILLUSIONS OF INTROSPECTION. 

cation. Yet we do not usually speak of introspectively 
recognizing a sensation. Our sense-impressions are 
marked off from all other feelings by having an ob- 
jective character, that is to say, an immediate relation to 
the external world, so that in attending to one of them 
our minds pass away from themselves in what Professor 
Bain calls the attitude of objective regard. Introspec- 
tion is confined to feelings which want this intimate 
connection with the external region, and includes 
sensation only so far as it is viewed apart from ex- 
ternal objects and on its mental side as a feeling, a 
process which is next to impossible where the sensa- 
tion has little emotional colour, as in the case of an 
ordinary sensation of sight or of articulate sound. 

This being so, errors of introspection, supposing 
such to be found, will in the main be sufficiently 
distinguished from those of perception. Even an hallu- 
cination of sense, whether setting out from a subjective 
sensation or not, always contains the semblance of a 
sense-impression, and so would not be correctly classed 
with errors of introspection. 

Just as introspection must be marked off from 
perception, so must it be distinguished from memory. 
It may be contended that, strictly speaking, all intro- 
spection is retrospection, since even in attending to a 
present feeling the mind is reflectively representing to 
itself the immediately preceding momentary experience 
of that feeling. Yet the adoption of this view does 
not hinder us from drawing a broad distinction be- 
tween acts of introspection and acts of memory. 
Introspection must be regarded as confined to the 
knowledge of immediately antecedent mental states 



SUBJECT DEFINED. 191 

with reference to which no error of memory can be 
supposed to arise. 

It follows from this that an illusion of introspection 
could only be found in connection with the appre- 
hension of present or immediately antecedent mental 
states. On the other hand, any illusions connected 
with the consciousness of personal continuity and iden- 
tity would fall rather under the class of mnemonic than 
that of introspective error. 

Once more, introspection must be carefully dis- 
tinguished from what I have called belief. Some of 
our beliefs may be found to grow out of and be 
compounded of a number of introspections. Thus, my 
conception of my own character, or my psychological 
conception of mind as a whole, may be seen to arise by 
a combination of the results of a number of acts of 
introspection. Yet, supposing this to be so, we must 
still distinguish between the single presentative act of 
introspection and the representative belief growing out 
of it. 

It follows from this that, though an error of the 
latter sort might conceivably have its origin in one of 
the former ; though, for example, a man's illusory 
opinion of himself might be found to involve errors of 
introspection, yet the two kinds of illusion would be 
sufficiently unlike. The latter would be a simple 
presentative error, the former a compound representa- 
tive error. 

Finally, in order to complete this preliminary 
demarcation of our subject-matter, it is necessary to 
distinguish between an introspection (apparent or real) 
of a feeling or idea, and a process of inference based 



192 ILLUSIONS OF INTROSPECTION. 

on this feeling. The term introspective knowledge 
must, it is plain, be confined to what is or appears to 
be in the mind at the moment of inspection. 

By observing this distinction, we are in a position 
to mark off an illusion of introspection from a fallacy 
of introspection. The former differs from the latter in 
the absence of anything like a conscious process of 
inference. Thus, if we suppose that the derivation 
by Descartes of the fact of the existence of God from 
his possession of the idea to be erroneous, such a con- 
sciously performed act of reasoning would constitute a 
fallacy rather than an illusion of introspection. 

We may, then, roughly define an illusion of intro- 
spection as an error involved in the apprehension of 
the contents of the mind at any moment. If we mis- 
take the quality or degree of a feeling or the structure 
of a complex mass of feeling, or if we confuse what is 
actually present to the mind with some inference 
based on this, we may be said to fall into an illusion 
of introspection. 

But here the question will certainly be raised : 
How can we conceive the mind erring as to the nature 
of its present contents ; and what is to determine, if 
not my immediate act of introspection, what is present 
in my mind at any moment? Indeed, to raise the 
possibility of error in introspection seems to do away 
with the certainty of presentative knowledge. 

If, however, the reader will recall what was said in 
an earlier chapter about the possibility of error in 
recognizing the quality of a sense-impression, he will 
be prepared for a similar possibility here. What we 
are accustomed to call a purely presentative cognition 



IS INTBOSPECTION FALLIBLE? 193 

is, in truth, partly representative. A feeling as pure 
feeling is not known ; it is only known when it is 
distinguished, as to quality or degree, and so classed 
or brought under some representation of a kind or 
description of feeling, as acute, painful, and so on. 
The accurate recognition of an impression of colour 
depends, as we have seen, on this process of classing 
being correctly performed. Similarly, the recognition 
of internal feelings implies the presence of the appro- 
priate or corresponding class-representation. Accord- 
ingly, if it is possible for a wrong representation to 
get substituted for the right one, there seems to be an 
opening for error. 

Any error that would thus arise can, of course, 
only be determined as such in relation to some other 
act of introspection of the same mind. In matters of 
internal perception other minds cannot directly assist 
us in correcting error as they can in the case of external 
perception, though, as we shall see by-and-by, they 
may do so indirectly. The standard of reality di- 
rectly applicable to introspective cognition is plainly 
what the individual mind recognizes at its best mo- 
ments, when the processes of attention and classify- 
ing are accurately performed, and the representation 
may be regarded with certainty as answering to the 
feeling. In other words, in the sphere of internal, 
as in that of external experience, the criterion of 
reality is the average and perfect, as distinguished 
from the particular variable and imperfect act of 
cognition. 

We see, then, that error in the process of intro- 
spection is at least conceivable. And now let us 



194 ILLUSIONS OF INTROSPECTION. 

examine this process a little further, in order to find 
out what probabilities of error attach to it. 

To begin with, then, an act of introspection, to be 
complete, clearly involves the apprehension of an in- 
ternal feeling or idea as something mental and marked 
off from the region of external experience. This dis- 
tinct recognition of internal states of mind as such, in 
opposition to external impressions, is by no means 
easy, but presupposes a certain degree of intellectual 
culture, and a measure of the power of abstract at- 
tention. 

Confusion of Internal and External Experience. 

Accordingly, we find that where this is wanting 
there is a manifest disposition to translate internal feel- 
ings into terms of external impressions. In this way 
there may arise a slight amount of habitual and 
approximately constant error. Not that the process 
approaches to one of hallucination ; but only that 
the internal feelings are intuited as having a cause or 
origin analogous to that of sense-impressions. Thus 
to the uncultivated mind a sudden thought seems like 
an audible announcement from without. The super- 
stitious man talks of being led by some good or evil 
spirit when new ideas arise in his mind or new reso- 
lutions shape themselves. To the simple intelligence 
of the boor every thought presents itself as an analogue 
of an audible voice, and he commonly describes his 
rough musings as saying this and that to himself. 
And this mode of viewing the matter is reflected even 
in the language of cultivated persons. Thus we say, 
'.' The idea struck me," or " was borne in on me," " I 



MIND AS POPULARLY CONCEIVED. 195 

was forced to do so and so," and so on, and in this 
manner we tend to assimilate internal to external 
mental phenomena. 

Much the same thing shows itself in our customary 
modes of describing our internal feelings of pleasure 
and pain. When a man in a state of mental depression 
speaks of having "a load" on his mind it is evident 
that he is interpreting a mental by help of an analogy 
to a bodily feeling. Similarly, when we talk of the 
mind being torn by doubt or worn by anxiety. It 
would seem as though we tended mechanically to 
translate mental pleasures and pains into the language 
of bodily sensations. 

The explanation of this deeply rooted tendency to 
a slightly illusory view of our mental states is, I think, 
an easy one. For one thing, it follows from the relation 
of the mental image to the sense-impression that we 
should tend to assimilate the former to the latter as 
to its nature and origin. This would account for the 
common habit of regarding thoughts, which are of 
course accompanied by representatives of their verbal 
symbols, as internal voices, a habit which is probably 
especially characteristic of the child and the uncivilized 
man, as we have found it to be characteristic of the 
insane. 

Another reason, however, must be sought for the 
habit of assimilating internal feelings to external sen- 
sations. If language has been evolved as an incident 
of social life, at once one of its effects and its causes, 
it would seem to follow that it must have first shaped 
itself to the needs of expressing these common objective 
experiences which we receive by way of our senses. 



196 ILLUSIONS OF INTKOSPECTION. 

Our habitual modes of thought, limited as they are 
by language, retain traces of this origin. We cannot 
conceive any mental process except by some vague 
analogy to a physical process. In other words, we can 
even now only think with perfect clearness when we 
are concerned with some object of common cognition. 
Thus, the sphere of external sensation and of physical 
agencies furnishes us with the one type of thinkable 
thing or object of thought, and we habitually view 
subjective mental states as analogues of these. 

Still, it may be said that these slight nascent errors 
are hardly worth naming, and the question would still 
appear to recur whether there are other fully developed 
errors deserving to rank along with illusions of sense. 
Do we, it may be asked, ever actually mistake the 
quality, degree, or structure of our internal feelings in 
the manner hinted above, and if so, what is the range 
of such error ? In order to appreciate the risks of such 
error, let us compare the process of self- observation with 
that of external perception with respect to the difficul- 
ties in the way of accurate presentative knowledge. 

Misreading of Internal Feelings. 

First of all, it is noteworthy that a state of con- 
sciousness at any one moment is an exceedingly com- 
plex thing. It is made up of a mass of feelings' and 
active impulses which often combine and blend in a 
most inextricable way. External sensations come in 
groups, too, but as a rule they do not fuse in apparently 
simple wholes as our internal feelings often do. The 
very possibility of perception depends on a clear dis- 
crimination of sense-elements, for example, the several 



DIFFICULTIES OF INTKOSPECTION. 197 

sensations of colour obtained by the stimulation of 
different parts of the retina. 1 But no such clearly 
defined mosaic of feelings presents itself in the internal 
region : one element overlaps and partly loses itself in 
another, and subjective analysis is often an exceedingly 
difficult matter. Our consciousness is thus a closely 
woven texture in which the mental eye often fails to 
trace the several threads or strands. Moreover, there 
is the fact that many of these ingredients are exceed- 
ingly shadowy, belonging to that obscure region of 
sub-consciousness which it is so hard to penetrate with 
the light of discriminative attention. This remark 
applies with particular force to that mass of organic 
feelings which constitutes what is known as coensesthesis, 
or vital sense. 

While, to speak figuratively, the minute anatomy 
of consciousness is thus difficult with respect to 
longitudinal sections of the mental column, it is no less 
difficult with respect to transverse sections. Under 
ordinary circumstances, external impressions persist so 
that they can be transfixed by a deliberate act of 
attention, and objects rarely flit over the external 
scene so rapidly as to allow us no time for a careful 
recognition of the impression. Not so in the case of 
the internal region of mind. The composite states of 
consciousness just described never remain perfectly 
uniform for the shortest conceivable duration. They 
change continually, just as the contents of the kaleido- 
scope vary with every shake of the instrument. Thus, 

1 I need hardly observe that physiology shows that there is no 
separation of different elementary colour-sensations which are locally 
identical. 



198 ILLUSIONS OF INTROSPECTION. 

one shade of feeling runs into another in such a way 
that it is often impossible to detect its exact quality ; 
and even when the character of the feeling does not 
change, its intensity is undergoing alterations so that 
an accurate observation of its quantity is impracticable. 
Also, in this unstable shifting internal scene features 
may appear for a duration too short to allow of close 
recognition. In this way it happens that we cannot 
sharply divide the feeling of the moment from its 
antecedents and its consequents. 

If, now, we take these facts in connection with 
what has been said above respecting the nature of the 
process of introspection, the probability of error will be 
made sufficiently clear. To transfix any particular 
feeling of the moment, to selectively attend to it, and 
to bring it under the proper representation, is an 
operation that requires time, a time which, though 
short, is longer than the fugitive character of so much 
of our internal mental life allows. From all of which 
it would appear to follow that it must be very easy to 
overlook, confuse, and transform, both as to quality 
and as to quantity, the actual ingredients of our in- 
ternal consciousness. 

From these sources there spring a number of small 
errors of introspection which, to distinguish them from 
others to be spoken of presently, may be called passive. 
These would include all errors in detecting what is in 
consciousness due to the intricacies of the phenomena, 
and not aided by any strong basis. For example, a 
mental state may fail to disclose its component parts to 
introspective attention. Thus, a motive may enter into 
our action which is so entangled with other feelings as to 



MIS-OBSERVATION OF FEELING. 199 

escape our notice. The fainter the feeling the greater 
the difficulty of detaching it and inspecting it in 
isolation. Again, an error of introspection may have 
its ground in the fugitive character of a feeling. If, 
for example, a man is asked whether a rapid action 
was a voluntary one, he may in retrospection easily 
imagine that it was not so, when as a matter of fact the 
action was preceded by a momentary volition. When 
a person exclaims, " I did a thing inadvertently or 
mechanically," it often means that he did not note the 
motive underlying the action. Such transitory feelings 
which cannot at the moment be seized by an act of 
attention are pretty certain to disappear at once, 
leaving not even a temporary trace in consciousness. 

We will now pass to the consideration of other 
illusions of introspection more analogous to what I have 
called the active illusions of perception. In our ex- 
amination of these we found that a pure representation 
may under certain circumstances simulate the appear- 
ance of a presentation, that a mental image may 
approximate to a sense-impression. In the case of the 
internal feelings this liability shows itself in a still 
more striking form. 

The higher feelings or emotions are distinguished 
from the simple sense-feelings in being largely repre- 
sentative. Thus, a feeling of contentment at any 
moment, though no doubt conditioned by the bodily 
state and the character of the organic sensations or 
ccensesthesis, commonly depends for the most part on 
intellectual representations of external circumstances 
or relations, and may be called an ideal foretaste of 
actual satisfactions, such as the pleasures of success, 



200 ILLUSIONS OF INTKOSPECTION. 

of companionship, and so on. This being so, it is 
easy for imagination to call up a semblance of these 
higher feelings. Since they depend largely on repre- 
sentation, a mere act of representation may suffice to 
excite a degree of the feeling hardly distinguishable 
from the actual one. Thus, to imagine myself as con- 
tented is really to see myself at the moment as actually 
contented. Again, the actor, though, as we shall see 
by-and-by, he does not feel all that the spectator is 
apt to attribute to him, tends, when vividly represent- 
ing to himself a particular shade of feeling,, to regard 
himself as actually feeling in this way. Thus, it is said 
of Garrick, that when acting Richard III., he felt 
himself for the moment to be a villain. 

We should expect from all this that in the act of 
introspection the mind is apt, within certain limits, to 
find what it is prepared to find. And since there is in 
these acts often a distinct wish to detect some par- 
ticular feeling, we can see how easy it must be for a 
man through bias and a wrong focussing of the atten- 
tion to deceive himself up to a certain point with 
respect to the actual contents of his mind. 

Let us examine one of these active illusions a 
little more fully. It would at first sight seem to be 
a perfectly simple thing to determine at any given 
moment whether we are enjoying ourselves, whether 
our emotional condition rises above the pleasure- 
threshold or point of indifference and takes on a 
positive hue of the agreeable or pleasurable. Yet 
there is good reason for supposing that people not 
unfrequently deceive themselves on this matter. It 
is, perhaps, hardly an exaggeration to say that most 



ACTIVE SELF-DECEPTION. 201 

of us are capable of imagining that we are having 
enjoyment when we conform to the temporary fashion 
of social amusement. It has been cynically observed 
that people go into society less in order to be happy 
than to seem so, and one may add that in this 
semblance of enjoyment they may, provided they are 
not blase, deceive themselves as well as others. The 
expectation of enjoyment, the knowledge that the 
occasion is intended to bring about this result, the 
recognition of the external signs of enjoyment in 
others — all this may serve to blind a man in the 
earlier stages of social amusement to his actual mental 
condition. 

If we look closely into this variety of illusion, we 
shall see that it is very similar in its structure and 
origin to that kind of erroneous perception which arises 
from inattention to the actual impression of the 
moment under the influence of a strong expectation 
of something different. The representation of our- 
selves as entertained dislodges from our internal field 
of vision our actual condition, relegating this to the 
region of obscure consciousness. Could we for a mo- 
ment get rid of this representation and look at the 
real feelings of the time, we should become aware 
of our error ; and it is possible that the process of 
becoming blase involves a waking up to a good deal of 
illusion of the kind. 

Just as we can thus deceive ourselves within certain 

limits as to our emotional condition, so we can mistake 

the real nature of our intellectual condition. Thus, 

when an idea is particularly grateful to our minds, we 

may easily imagine that we believe it, when in point 
10 



202 ILLUSIONS OF INTROSPECTION. 

of fact all the time there is a sub-conscious process ot 
criticism going on, which if we attended to it for a 
moment would amount to a distinct act of disbelief. 
Some persons appear to be capable of going on habitu- 
ally practising this petty deceit on themselves, that is 
to say, imagining they believe what in fact they are 
strongly inclined to doubt. Indeed, this remark applies 
to all the grateful illusions respecting ourselves and 
others, which will have to be discussed by-and-by. 
The impulse to hold to the illusion in spite of critical 
reflection, involves the further introspective illusion of 
taking a state of doubt for one of assurance. Thus, the 
weak, flattered man or woman manages to keep up a 
sort of fictitious belief in the truth of the words which 
are so pleasant to the ear. 

It is plain that the external conditions of life 
impose on the individual certain habits of feeling 
which often conflict with his personal propensities. 
As a member of society he has a powerful motive to 
attribute certain feelings to himself, and this motive 
acts as a bias in disturbing his vision of what is actually 
in his mind. While this holds good of lighter matters, 
as that of enjoyment just referred to, it applies still 
more to graver matters. Thus, for example, a man 
may easily pursuade himself that he feels a proper 
sentiment of indignation against a perpetrator of some 
mean or cruel act, when as a matter of fact his feeling 
is much more one of compassion for the previously 
liked offender. In this way we impose on ourselves, 
disguising our real sentiments by a thin veil of make- 
believe. 

So far I have spoken of an illusion of introspection 



MAL-OBSEEVATION OF FEELING. 203 

as analogous to the slight misapprehensions of sense- 
impression which were touched on in connection with 
illusions of sense (Chapter III.). It is to be observed, 
however, that the confusing of elements of conscious- 
ness, which is so prominent a factor in introspective 
illusion, involves a species of error closely analogous to a 
complete illusion of perception, that is to say, one which 
involves a misinterpretation of a sense-impression. 

This variety of illusion is illustrated in the case in 
which a present feeling or thought is confounded with 
some inference based on it. For example, a present 
thought may, through forgetfulness, be regarded as a 
new discovery. Its originality appears to be im- 
mediately made known in the very freshness which 
characterizes it. Every author probably has undergone 
the experience of finding that ideas which started 
up to his mind as fresh creations, were unconscious 
reminiscences of his own or of somebody else's ideas. 

In the case of present emotional states this liability 
to confuse the present and the past is far greater. 
Here there is something hardly distinguishable from 
an active illusion of sense-perception. In this con- 
dition of mind a man often- says that he has an " in- 
tuition" of something supposed to be immediately 
given in the feeling itself. For instance, one whose 
mind is thrilled by the pulsation of a new joy ex- 
claims, " This is the happiest moment of my life," 
and the assurance seems to be contained in the very 
intensity of the feeling itself. Of course, cool re- 
flection will tell him that what he affirms is merely 
a belief, the accuracy of which presupposes processes 
of recollection and judgment, but to the man's mind 



204 ILLUSIONS OF INTEOSPECTION. 

at the moment the supremacy of this particular joy 
is immediately intuited. And so with the assurance 
that the present feeling, for example of love, is un- 
dying, that it is equal to the most severe trials, and 
so on. A man is said to feel at the moment that it is 
so, though as the facts believed have reference to 
absent circumstances and events, it is plain that the 
knowledge is by no means intuitive. 

At such times our minds are in a state of pure 
feeling : intellectual discrimination and comparison are 
no longer possible. In this way our emotions in the 
moments of their greatest intensity carry away our 
intellects with them, confusing the region of pure 
imagination with that of truth and certainty, and 
even the narrow domain of the present with the vast 
domain of the past and future. In this condition 
differences of present and future may be said to dis- 
appear and the energy of the emotion to constitute 
an immediate assurance of its existence absolutely. 1 

The great region for the illustration of these active 
illusions is that of the moral and religious life. With 
respect to our real motives, our dominant aspirations, 
and our highest emotional experiences, we are greatly 
liable to deceive ourselves. The moralist and the 
theologian have clearly recognized the possibilities of 
self-deception in matters of feeling and impulse. To 

1 This kind of error is, of course, common to all kinds of cognition, 
in so far as they involve comparison. Thus, the presence of the ex- 
citement of the emotion of wonder at the sight of an unusually large 
object, say a mountain, disposes the mind to look on it as the largest 
of its class. Such illusions come midway between presentative and 
representative illusions. They might, perhaps, be specially marked 
off as illusions of "judgment." 



MORAL SELF-SCRUTINY. 205 

them it is no mystery that the human heart should 
mistake the fictitious for the real, the momentary and 
evanescent for the abiding. And they have recognized, 
too, the double bias in these errors, namely, the powerful 
disposition to exaggerate the intensity and persistence 
of a present feeling on the one hand, and on the other 
hand to take a mere wish to feel in a particular way for 
the actual possession of the feeling. 

Philosophic Illusions. 

The opinion of theologians respecting the nature of 
moral introspection presents a singular contrast to that 
entertained by some philosophers as to the nature of 
self-consciousness. It is supposed by many of these 
that in interrogating their internal consciousness thev 
are lifted above all risk of error. The " deliverance of 
consciousness " is to them something bearing the seal 
of a supreme authority, and must not be called in 
question. And so they make an appeal to individual 
consciousness a final resort in all matters of philo- 
sophical dispute. 

JSTow, on the face of it, it does not seem probable 
that this operation should have an immunity from all 
liability to error. For the matters respecting which 
we are directed to introspect ourselves, are the most 
subtle and complex things of our intellectual and 
emotional life. And some of these philosophers even 
go so far as to affirm that the plain man is quite equal 
to the niceties of this process. 

It has been brought as a charge against some of 
these same philosophers that they have based certain 
of their doctrines on errors of introspection. This 



20o" ILLUSIONS OF INTROSPECTION. 

charge must, of course, be received with some sort of 
suspicion here, since it has been brought forward by- 
avowed disciples of an opposite philosophic school. 
Nevertheless, as there is from our present disinterested 
and purely scientific point of view a presumption that 
philosophers like other men are fallible, and since it is 
certain that philosopical introspection does not materi- 
ally differ from other kinds, it seems permissible just 
to glance at some of these alleged illusions in relation 
to other and more vulgar forms. Further reference to 
them will be made at the end of our study. 

These so-called philosophical illusions will be found, 
like the vulgar ones just spoken of, to illustrate the 
distinction drawn between passive and active illusions. 
That is to say, the alleged misreading of individual 
consciousness would result now from a confusion of 
distinct elements, including wrong suggestion, due to 
the intricacies of the phenomena, now from a powerful 
predisposition to read something into the phenomena. 

A kind of illusion in which the passive element 
seems most conspicuous would be the error into which 
the interrogator of the individual consciousness is said 
to fall respecting simple unanalyzable states of mind. 
On the face of it, it is not likely that a mere inward 
glance at the tangle of conscious states should suffice 
to determine what is such a perfectly simple mental 
phenomenon. Accordingly, when a writer declares 
that an act of introspection demonstrates the simple 
unanalyzable character of such a feeling as the senti- 
ment of beauty or that of moral approval, the opponent 
of this view clearly has some show of argument for 
saying that this simplicity may be altogether illusory 



MIS -INTROSPECTION IN PHILOSOPHY. 207 

and due to the absence of a perfect act of attention. 
Similarly, when it is said that the idea of space 
contains no representations of muscular sensation, the 
statement may clearly arise from the want of a 
sufficiently careful kind of introspective analysis. 1 

In most cases of these alleged philosophical errors, 
however, the active and passive factors seem to com- 
bine. There are certain intricacies in the mental 
phenomenon itself favouring the chances of error, and 
there are independent predispositions leading the mind 
to look at the phenomenon in a wrong way. This 
seems to apply to the famous declaration of a certain 
school of thinkers that by an act of introspection we 
can intuit the fact of liberty, that is to say, a power 
of spontaneous determination of action superior to and 
regulative of the influence of motives. It may be 
plausibly contended that this idea arises partly from 

1 So far as any mental state, though originating in a fusion of 
elements, is now unanalyzable by the best effort of attention, we must 
of course regard it in its present form as simple. This distinction 
between what is simple or complex in its present nature, and what is 
originally so, is sometimes overlooked by psychologists. Whether the 
feelings and ideas here referred to are now simple or complex, cannot, 
I think, yet be very certainly determined. To take the idea of space, 
I find that after practice I recognize the ingredient of muscular 
feeling much better than I did at first. And this exactly answers to 
Helmholtz's contention that elementary sensations as partial tones 
can be detected after practice. Such separate recognition may be 
said to depend on correct representation. On the other hand, it must 
be allowed that there is room for the intuitionist to say that the 
associationist is here reading something into the idea which does not 
belong to it. It is to be added that the illusion which the associa- 
tionist commonly seeks to fasten on his opponent is that of confusing 
final with original simplicity. Thus, he says that, though the idea of 
space may now to all intents and purposes be simple, it was really 
built up out of many distinct elements. More will be said on tho 
relation of questions of nature and genesis further on. 



208 ILLUSIONS OF INTROSPECTION. 

a mixing up of facts of present consciousness with 
inferences from them, and partly from a natural predis- 
position of the mind to invest itself with this supreme 
power of absolute origination. 1 

In a similar way, it might be contended that other 
famous philosophic dicta are founded on a process of 
erroneous introspection of subjective mental states. In 
isome cases, indeed, it seems a plausible explanation to 
regard these illusions as mere survivals in attenuated 
shadowy form of grosser popular illusions. But this 
is not yet the time to enter on these, which, moreover 
hardly fall perhaps under our definition of an illusion 
of introspection. 

Value of the Introspective Method. 

In drawing up this rough sketch of the illusions of 
introspection, I have had no practical object in view. 
I have tried to look at the facts as they are apart from 
any conclusions to be drawn from them. The question 
how far the liability to error in any region of inquiry 
vitiates the whole process is a difficult one; and the 
question whether the illusions to which we are subject 
in introspection materially affect the value of self- 
knowledge as a whole and consequently of the intro- 
spective method in psychology, as many affirm, is too 
subtle a one to be fully treated now. All that I shall 
attempt here is to show that it does not do this any 
more than the risk of sense-illusion can be said 
materially to affect the value of external observation. 

1 I may as well be frank and say that I myself, assuming free-will 
to be an illusion, have tried to trace the various threads of influence 
which have contributed to its remarkable vitality. (See Sensation and 
Intuition, ch. v., " The Genesis of the Free-Will Doctrine.") 



IS INTROSPECTION VALUELESS? 209 

It is to be noted first of all that the errors of 
introspection are much more limited than those of 
sense-perception. They broadly answer to the slight 
errors connected with the discrimination and recogni- 
tion of the sense-impression. There is nothing 
answering to a complete hallucination in the sphere 
of the inner mental life. It follows, too, from what has 
been said above, that the amount of active error in 
introspection is insignificant, since the representation 
of a feeling or belief is so very similar to the actual 
experience of it. 

In brief, the errors of introspection, though 
numerous, are all too slight to render the process of 
introspection as a whole unsound and untrustworthy. 
Though, as we have seen, it involves, strictly speaking, 
an ingredient of representation, this fact does not do 
away with the broad distinction between presentative 
and representative cognition. Introspection is pre- 
sentative in the sense that the reality constituting the 
object of cognition, the mind's present feeling, is as 
directly present to the knowing mind as anything can 
be conceived to be. It may be added that the power 
of introspection is a comparatively new acquisition of 
the human race, and that, as it improves, the amount 
of error connected with its operation may reasonably 
be expected to become infinitesimal. 

It is often supposed by those who undervalue the 
introspective method in psychology that there is a 
special difficulty in the detection of error in intro- 
spection, owing to the fact that the object of inspection 
is something individual and private, and not open to 
common scrutiny as the object of external perception. 



210 ILLUSIONS OF INTROSPECTION. 

Yet, while allowing a certain force to this objection 
I would point out, first of all, that even in sense-percep- 
tion, what the individual mind is immediately certain 
of is its own sensations. The relatively perfect cer- 
tainty which finally attaches to the presentative side 
of sense-perception is precisely that which finally at- 
taches to the results of introspection. 

In the second place, it may be said that the con- 
trast between the inner and the outer experience is 
much less than it seems. In many cases our emotions 
are the direct result of a common external cause, and 
even when they are not thus attached to some present 
external circumstance, we are able, it is admitted, by 
the use of language, roughly to compare our individual 
feelings. And such comparison is continually bring- 
ing to light the fact that there is a continuity in our 
mental structure, that our highest thoughts and 
emotions lead us back to our common sense-impres- 
sions, and that consequently, in spite of all individual 
differences of temperament and mental organization 
our inner experience is in all its larger features a 
common experience. 

I may add that this supposition of the common 
nature of our internal experience, as a whole, not only 
underlies the science of psychology, but is implied in 
the very process of detecting and correcting errors of 
introspection. I do not mean that in matters of 
feeling " authority " is to override "private judgment.'' 
Our last resort with respect to things of the mind is, 
as I have said, that of careful self-inspection. And 
the progress of psychology and the correction of illu- 
sion proceed by means of an ever-improving exercise 



VALUE OF INTEOSPECTIVE METHOD. 211 

of the introspective faculty. Yet such, individual 
inspection can at least be guided by the results of 
others' similar inspection, and should be so guided as 
soon as a general consensus in matters of internal ex- 
perience is fairly made out. In point of fact, the 
preceding discussion of illusions of introspection has 
plainly rested on the sufficiently verified assumption 
that the calmest and most efficient kind of introspec- 
tion, in bringing to light what is permanent as com- 
pared with what is variable in the individual cognition, 
points in the direction of a common body of intro- 
spected fact. 



CHAPTER IX 

OTHEB QUASI-PEESENTATTVE ILLUSIONS: EBEOES OF 
INSIGHT. 

Besides the perception of external objects, and the 
inspection of our internal mental states, there are other 
forms of quasi-presentative cognition which need to 
be touched on here, inasmuch as they are sometimes 
erroneous and illusory. 

In the last chapter I alluded to the fact that 
emotion may arise as the immediate accompaniment 
of a sense-impression. When this is the ca?e there 
is a disposition to read into the external object a 
quality answering to the emotion, just as there is a 
disposition to ascribe to objects qualities of heat and 
cold answering to the sensations thus called. And 
such a reference of an emotional result to an external 
exciting cause approximates in character to an im- 
mediate intuition. The cognition of the quality is 
instantaneous, and quite free from any admixture of 
conscious inference. Accordingly, we have to inquire 
into the illusory forms of such intuition, if such 
there be. 



EMOTIONAL PERCEPTS. 213 

JEstlietic Intuition. 

Conspicuous among these quasi-presentative emo- 
tional cognitions is aesthetic intuition, that is to say, 
the perception of an object as beautiful. It is not 
necessary here to raise the question whether there is, 
strictly speaking, any quality in things answering to 
the sentiment of beauty in our minds : this is a philo- 
sophical and not a psychological question, and turns on 
the further question, what we mean by object. All that 
we need to assume here is that there are certain aspects 
of external things, certain relations of form, together 
with a power of exciting certain pleasurable ideas in 
the spectator's mind, which are commonly recognized 
as the cause of the emotion of beauty, and indeed 
regarded as constituting the embodiments of the ob- 
jective quality, beauty. ^Esthetic intuition thus clearly 
implies the immediate assurance of the existence of a 
common source of aesthetic delight, a source bound up 
with an object of common sense-perception. And so 
we may say that to call a thing beautiful is more or 
less distinctly to recognize it as a cause of a present 
emotion, and to attribute to it a power of raising a 
kindred emotion in other minds. 

JEstlietie Illusion. 

According to this view of the matter, an illusion of 
aesthetic intuition would arise whenever this power of 
affecting a number of minds pleasurably is wrongly 
attributed, by an act of " intuition," to an object of 
sense-perception, on the ground of a present personal 
feeling. 



214 OTHER QUASI-PEESENTATIVE ILLUSIONS. 

Now, this error is by no means nnfrequent. Oar 
delight in viewing external things, though agreeing 
np to a certain point, does not agree throughout. It 
is a trite remark that there is a large individual 
factor, a considerable " personal equation," in matters 
of taste, as in other matters. Permanent differences of 
natural sensibility, of experience, of intellectual habits, 
and so on, make an object aesthetically impressive and 
valuable to one man and not to another. Yet these 
differences tend to be overlooked. The individual 
mind, filled with delight at some spectacle, auto- 
matically projects its feeling outwards in the shape of 
a cause of a common sentiment. And the force of 
'this impulse cannot be altogether explained as the 
effect of past experiences and of association. It seems 
to involve, in addition, the play of social instincts, the 
impulse of the individual mind to connect itself in 
sympathy with the collective mind. 

Here, as in the other varieties of illusion already 
treated of, we may distinguish between a passive and 
an active side ; only in this case the passive side must 
not be taken as corresponding to any common sug- 
gestions of the object, as in the case of perception 
proper. So far as an illusion of aesthetic intuition may 
be considered as passive, it must be due to the effect of 
circumscribed individual associations with the object. 

All agree that what is called beauty consists, to a 
considerable extent, of a power of awaking pleasant 
suggestions, but in order that these should constitute 
a ground of aesthetic value, they must be common, par- 
ticipated in by all, or at least by an indefinite number. 
This will be the case when the association rests on our 



SUBJECTIVE AND OBJECTIVE BEAUTY. 215 

common every-day experiences, and our common know- 
ledge of things, as in the case of the peaceful beauty 
of an ascending curl of blue smoke in a woody land- 
scape, or the awful beauty of a lofty precipice. On 
the other hand, when the experience and recollections, 
which are the source of the pleasure, are restricted and 
accidental, any attribution of objective worth is illu- 
sory. Thus, the ascription of beauty to one's native 
village, to one's beloved friends, and so on, in so far as 
it carries the conviction of objective worth, may imply 
a confusion of the individual with the common ex- 
perience. 

The active side of this species of illusions would be 
illustrated in every instance of ascribing beauty to 
objects which is due, in a considerable measure at 
least, to some pre-existing disposition in the mind, 
whether permanent or temporary. A man brings his 
peculiar habits of thought and feeling to the con- 
templation of objects, and the aesthetic impression 
produced is coloured by these predispositions. Thus, 
a person of a sad and gloomy cast of mind will be 
disposed to see a sombre beauty where other eyes see 
nothing of the kind. And then there are all the 
effects of temporary conditions of the imagination and 
the feelings. Thus, the individual mind may be 
focussed in a certain way through the suggestion of 
another. People not seldom see a thing to be beauti- 
ful because they are told that it is so. It might not 
be well to inquire too curiously how many of the 
frequenters of the annual art exhibitions use their 
own eyes in framing their aesthetic judgments. Or 
the temporary predisposition may reside in a purely 



216 OTHER QUASI-PEESENTATIVE ILLUSIONS. 

personal feeling or desire uppermost at the time. Our 
enjoyment of nature or of art is coloured by our 
temporary mood. There are moments of exceptional 
mental exhilaration, when even a commonplace scene 
will excite an appreciable kind of admiration. Or 
there may be a strong wish to find a thing beautiful 
begotten of another feeling. Thus, a lover desires to 
find beauty in his mistress ; or, having found it in her 
face and form, desires to find a harmonious beauty in 
her mind. In these different ways temporary acci- 
dents of personal feeling and imagination enter into 
and determine our aesthetic intuition, making it deviate 
from the common standard. This kind of error may 
even approximate in character to an hallucination of 
sense when there is nothing answering to a common 
source of aesthetic pleasure. Thus, the fond mother, 
through the very force of her affection, will construct 
a beauty in her child, which for others is altogether 
non-existent. 

What applies to the perception of beauty in the 
narrow sense will apply to all other modes of aesthetic 
intuition, as that of the sublime and the ludicrous, and 
the recognition of the opposite of beauty or the ugly. 
In like manner, it will apply to moral intuition in so 
far as it is an instantaneous recognition of a certain 
quality in a perceived action based on, or at least con- 
joined with, a particular emotional effect. In men's 
intuitive judgments respecting the right and the wrong, 
the noble and base, the admirable and contemptible, 
and so on, we may see the same kind of illusory, 
universalizing of personal feeling as we have seen in 
their judgments respecting the beautiful. And the 



KNOWLEDGE OF OTHEKS' FEELINGS. 217 

sources of the error are the same in the two eases. 
Accidents of experience, giving special associations to 
the actions, will not unfrequently warp the individual 
intuition. Ethical culture, like aesthetic culture, means 
a continual casting aside of early illusory habits of 
intuition. And further, moral intuition illustrates all 
those effects of feeling which we have briefly traced in 
the case of aesthetic intuition. The perversions of the 
moral intuition under the sway of prejudice are too 
familiar to need more than a bare allusion. 



Nature of Insight. 

There remains one further mode of cognition which 
approximates in character to presentative knowledge, 
and is closely related to external perception. I refer 
to the commonly called " intuitive " process by which 
we apprehend the feelings and thoughts of other minds 
through the external signs of movement, vocal sound, 
etc., which make up expression and language. This 
kind of knowledge, which is not sufficiently marked off 
from external perception on the one side and intro- 
spection on the other, I venture to call Insight. 

I am well aware that this interpretation of the 
mental states of others is commonly described as a 
process of inference involving a conscious reference to 
our own similar experiences. I willingly grant that it 
is often so. At the same time, it must be perfectly 
plain that it is not always so. It is, indeed, doubtful 
whether in its first stages in early life it is invariably so, 
for there seem to be good reasons for attributing to the 
infant mind a certain degree of instinctive or inherited 



218 OTHER QUASI-rEESENTATIVE ILLUSIONS 

capability in making out the looks and tones of others. 1 
And, however this may be, it is certain that with the 
progress of life a good part of this interpretation comes 
to be automatic or unconscious, approximating in 
character to a sense-perception. To recognize content- 
ment in a placid smile is, one would say, hardly less 
immediate and intuitive than to recognize the coolness 
of a stream. 

We must, of course, all allow that the fusion of 
the presentative and the representative element is, 
speaking generally, more complete in the case of sense- 
perception than in that here considered. In spite of 
Berkeley's masterly account of the rationale of visual 
perception as an interpretation of " visual language " 
and all that has confirmed it, the plain man cannot, at 
the moment of looking at an object, easily bring him- 
self to admit that distance is not directly present to his 
vision. On the other hand, on cool reflection, he will 
recognize that the complacent benevolent sentiment is 
distinct from the particular movements and changes in 
the eye and other features which express it. Yet, while 
admitting this, I must contend that there is no very 
hard and fast line dividing the two processes, but that 
the reading of others' feelings approximates in charac- 
ter to an act of perception. 

An intuitive insight may, then, be defined as that 
instantaneous, automatic, or " unconscious " mode of 

1 I purposely leave aside here the philosophical question, whether 
the knowledge of others' feelings is intuitive in the sense of being 
altogether independent of experience, and the manifestation of a 
fundamental belief. The inherited power referred to in the text 
might, of course, be viewed as a transmitted result of ancestral 
experience. 



INSIGHT AND PERCEPTION. 219 

interpreting another's feeling which occurs whenever 
the feeling is fully expressed, and when its signs are 
sufficiently familiar to us. This definition will include 
the interpretation of thoughts by means of language, 
though not, of course, the belief in an objective fact 
grounded on a recognition of another's belief. On the 
other hand, it will exclude all the more complex inter- 
pretations of looks and words which imply conscious 
comparison, reflection, and reasoning. Further, it will 
exclude a large part of the interpretation of actions as 
motived, since this, though sometimes approaching the 
intuitive form, is for the most part a process of con- 
jectural or doubtful inference, and wanting in the 
immediate assurance which belongs to an intuitive 
reading of a present emotion or thought. 

From this short account of the process of insight, its 
relation to perception and introspection becomes pretty 
plain. On the one hand, it closely resembles sense- 
perception, since it proceeds by the interpretation of a 
sense-impression by means of a representative image. 
On the other hand, it differs from sense-perception, and 
is more closely allied to introspection in the fact that, 
while the process of interpretation in the former case 
is a reconstruction of external experiences, in the latter 
case it is a reconstruction of internal experiences. To 
intuit another's feeling is clearly to represent to our- 
selves a certain kind of internal experience previously 
known, in its elements at least, by introspection, while 
these represented experiences are distinctly referred to 
another personality. 

And now we see what constitutes the object of 
insight. This is, in part, a common experience, as in 



220 OTHER QUASI-PEESENTATIVE ILLUSIONS. 

the case of sense-perception and sesthetic intuition, 
since to perceive another's feeling is implicitly to 
cognize the external conditions of a common insight. 
But this is clearly not the whole, nor even the main 
part of objective reality in this act of cognition. An 
intuitive insight differs from a sense-perception in that 
it involves an immediate assurance of the existence of 
a feeling presentatively known, though not to our own 
minds. The object in insight is thus a presentative 
feeling as in introspection, though not our own, but 
another's. And so it differs from the object in sense- 
perception in so far as this last involves sense-experi- 
ences, as muscular and tactual feelings, which are not 
at the moment presentatively known to any mind. 

Illusions of Insight. 

And now we are in a position, perhaps, to define an 
illusion of insight, and to inquire whether there is any- 
thing answering to our definition. An illusory insight 
is a quasi-intuition of another's feelings which does 
not answer to the internal reality as presentatively 
known to the subject himself. In spite of the errors 
of introspection dealt with in the last chapter, nobody 
will doubt that, when it is a question between a man's 
knowing what is at the moment in his own mind and 
somebody else's knowing, logic, as well as politeness, 
requires us to give precedence to the former. 

An illusion of insight, like the other varieties of 
illusion already dealt with, may arise either by way of 
wrong suggestion or by way of a warping preconception. 
Let us look at each of these sources apart. 

Our insights, like our perceptions, though intuitive 



FASSIVE ILLUSIONS OF INSIGHT. 221 

in form, are obviously determined by previous ex- 
perience, association, and habit. Hence, on its passive 
side, an illusion of insight may be described as a wrong 
interpretation of a new or exceptional case. !For 
example, having associated the representation of a 
slight feeling of astonishment with uplifted eyebrows, 
we irresistibly tend to see a face in which this is a con- 
stant feature as expressing this particular shade of 
emotion. In this way we sometimes fall into grotesque 
errors as to mental traits. And the most practised 
physiognomist may not unfrequently err by importing 
the results of his special circle of experiences into new 
and unlike cases. 

Much the same thing occurs in language. Our 
timbre of voice, our articulation, and our vocabulary, 
like our physiognomy, have about them something 
individual, and error often arises from overlooking- this, 
and hastily reading common interpretations into 
exceptional cases, The misunderstandings that arise 
even among the most open and confiding friends 
sufficiently illustrate this liability to error. 

Sometimes the error becomes more palpable, as, for 
example, when we visit another country. A foreign 
language, when heard, provokingly suggests all kinds 
of absurd meanings through analogies to our familiar 
tongue. Thus, the Englishman who visits Germany 
cannot, for a time, hear a lady use the expression, 
" Mein Mann," without having the amusing suggestion 
that the speaker is wishing to call special attention to 
the fact of her husband's masculinity. And doubtless 
the German who visits us derives a similar kind of 
amusement from such involuntary comparisons. 



222 OTHER QUASI-PRESENTATIVE ILLUSIONS. 

A fertile source of illusory insight is, of course, 
c nscious deception on the part of others. The rules 
of polite society require us to be hypocrites in a small 
way, and we have occasionally to affect the signs of 
amiability, interest, and amusement, when our actual 
sentiment is one of indifference, weariness, or even 
positive antipathy. And in this way a good deal of 
petty illusion arises. Although we may be well 
aware of the general untrustworthiness of this society 
behaviour, such is the force of association and habit, 
that the bland tone and flattering word irresistibly 
excite a momentary feeling of gratification, an effect 
which is made all the more easy by the co-operation of 
the recipient's own wishes, touched on in the last 
chapter. 

Among all varieties of this deception, that of the 
stage is the most complete. The actor is a man who 
has elaborately trained himself in the simulation of 
certain feelings. And when his acting is of the best 
quality, and the proper bodily attitude, gesture, tone of 
voice, and so on, are hit off, the force of the illusion 
completely masters us. For the moment we lose sight of 
the theatrical surroundings, and see the actor as really 
carried away by the passion which he so closely imi- 
tates. Histrionic illusion is as complete as any artistic 
variety can venture to be. 1 

I have said that our insights are limited by our 

own mental experience, and so by introspection. In 

truth, every interpretation of another's look and word 

1 I here assume, along wilh G. H. Lewes and other competent 
dramatic critics, that the actor does not and dares not feel what ha 
expresses, at least not in the perfectly spontaneous way, and in the 
tame measure in which he appears to feel it. 



ACTIVE ILLUSIONS OF INSIGHT. 223 

is determined ultimately, not by what we have pre- 
viously observed in others, but by what we have 
personally felt, or at least have in a sense made our 
own by intense sympathy. Hence we may, in general, 
regard an illusion of insight on the active side as a 
hasty projection of or.r own feelings, thoughts, etc., 
into other minds. 

We habitually approach others with a predis- 
position to attribute to them our own modes of think- 
ing and feeling. And this predisposition will be the 
more powerful, the more desirous we are for sym- 
pathy, and for that confirmation of our own views 
which the reflection of another mind affords. Thus, 
when making a new acquaintance, people are in 
general disposed to project too much of themselves 
into the person who is the object of inspection. They 
intuitively endow him with their own ideas, ways of 
looking at things, prejudices of sentiment, and so on, 
and receive something like a shock when later on 
they find out how different he is from this first hastily 
formed and largely performed image. 

The same thing occurs in the reading of literature, 
and the appreciation of the arts of expression generally. 
We usually approach an author with a predisposition 
to read our own habits of thought and sentiment into 
his words. It is probably a characteristic defect of a 
good deal of current criticism of remote writers to 
attribute to them too much of our modern conceptions 
and aims. Similarly, we often import our own special 
feelings into the utterances of the poet and of the 
musical composer. That much of this intuition is 
illusory, may be seen by a little attention to the " in- 



224 OTHER QUASI- PRESENTATIVE ILLUSIONS 

tuitions " of different critics. Two readers of unlike 
emotional organization will find incompatible modes of 
feeling in the same poet. And everybody knows bow 
common it is for musical critics and amateurs to dis- 
cover quite dissimilar feelings in the same com- 
position. 1 

The effect of this active projection of personal 
feeling will, of course, be seen most strikingly when 
there is a certain variety of feeling actually excited at 
the time in the observer's mind. A man who is in 
a particularly happy mood tends to reflect his 
exuberant gladness on others. The lover, in the 
moment of exalted emotion, reads a response to all his 
aspirations in his mistress's eyes. Again, a man will 
tend to project his own present ideas into the minds of 
others, and so imagine that they know what he knows ; 
and this sometimes leads to a comical kind of 
embarrassment, and even to a betrayal of some- 
thing which it was the interest of the person to keep 
to himself. Once more, in interpreting language, we 
may sometimes catch ourselves mistaking the mean- 
ing, owing to the presence of a certain idea in the 
mind at the time. Thus, if I have just been thinking 
of Comte, and overhear a person exclaim, " I'm posi- 
tive," I irresistibly tend, for the moment, to ascribe to 
him an avowal of discipleship to the great positivist. 

Poetic Illusion. 

The most remarkable example of this projection of 

1 The illusory nature of much of this emotional interpretation of 
music has been ably exposed by Mr. Gurney. (See The Power of 
Sound, p. 345, et seq.) 



PERSONIFICATION OF NATURE. 225 

feeling is undoubtedly illustrated in the poetic inter- 
pretation of inanimate nature. The personification of 
tree, mountain, ocean, and so on, illustrates, no doubt, 
the effect of association and external suggestion ; 
for there are limits to such personification. But 
resemblance and suggestion commonly bear, in this 
case, but a small proportion to active constructive 
imagination. One might, perhaps, call this kind of 
projection the hallucination of insight, since there is 
nothing objective corresponding to the interpretative 
image. 

The imaginative and poetic mind is continually 
on the look out for hints of life, consciousness, and 
emotion in nature. It finds a certain kind of satis- 
faction in this half-illusory, dream-like transformation 
of nature. The deepest ground of this tendency 
must probably be looked for in the primitive ideas of 
the race, and the transmission by inheritance of the 
effect of its firmly fixed habits of mind. The un- 
disciplined mind of early man, incapable of distin- 
guishing the object of perception from the product of 
spontaneous imagination, and taking his own double 
existence as the type of all existence, actually saw the 
stream, the ocean, and the mountain as living beings ; 
and so firmly rooted is this way of regarding objects, 
that even our scientifically trained minds find it a 
lelief to relapse occasionally into it. 1 

While there is this general imaginative disposition 
in the poetic mind to endow nature with life and con- 

1 The reader "will note that this impulse is complementary to tlie 
other impulse to view all mental states as analogous to impressions 
produced by external things, on which I touched in the last chapter 

11 



226 OTHEE QUASI-PRESENTATIVE ILLUSIONS. 

sciousness, there are special tendencies to project the 
individual feelings into objects. Every imaginative 
mind looks for reflections of its own deepest feelings 
in the world about it. The lonely embittered heart, 
craving for sympathy, which he cannot meet with in 
his fellow-man, finds traces of it in the sighing of the 
trees or the moaning of the sad sea-wave. Our Poet 
Laureate, in his great elegy, has abundantly illustrated 
this impulse of the imagination to reflect its own 
emotional colouring on to inanimate things: for ex- 
ample in the lines — 

" The wild unrest that lives in woe 

Would dote and pore on yonder cloud 

That rises upward always higher, 

And onward drags a labouring breast, 
And topples round the dreary west, 

A looming bastion fringed with fire." 

So far I have been considering active illusions of 
insight as arising through the play of the impulse of 
the individual mind to project its feelings outwards, 
or to see their reflections in external things. I must 
now add that active illusion may be due to causes 
similar to those which we have seen to operate in the 
sphere of illusory perception and introspection. That 
is to say, there may be a disposition, permanent or 
temporary, to ascribe a certain kind of feeling to others 
in accordance with our wishes, fears, and so on. 

To give an illustration of the permanent causes, it 
is well known that a conceited man will be disposed to 
attribute admiration of himself to others. On the 
other hand, a shy, timid person will be prone to read 
into other minds the opposite kind of feeling. 



EXPECTATION AND INSIGHT. 227 

Coming to temporary forces, we find that any ex- 
pectation to meet with a particular kind of mental 
trait in a new acquaintance will dispose the observer 
hastily and erroneously to attribute corresponding feel- 
ings to the person. And if this expectation springs 
out of a present feeling, the bias to illusory insight is 
still more powerful. For example, a child that fears 
its parent's displeasure will be prone to misinterpret 
the parent's words and actions, colouring them accord- 
ing to its fears. So an angry man, strongly desirous of 
making out that a person has injured him, will be 
disposed to see signs of conscious guilt in this person's 
looks or words. Similarly, a lover will read fine 
thoughts or sentiments into the mind of his mistress 
under the influence of a strong wish to admire. 

And what applies to the illusory interpretation of 
others' feelings applies to the ascription of feelings to 
inanimate objects. This is due not simply to the 
impulse to expand one's conscious existence through 
far-reaching resonances of sympathy, but also to a 
permanent or temporary disposition to attribute a cer- 
tain kind of feeling to an object. Thus, the poet per- 
sonifies nature in part because his emotional cravings 
prompt him to construct the idea of something that 
can be admired or worshipped. Once more, the action 
of a momentary feeling when actually excited is seen 
in the "mechanical" impulse of a man to retaliate 
when he strikes his foot against an object, as a chair, 
which clearly involves a tendency to attribute an inten- 
tion to hurt to the unoffending body, and the rationale 
of which odd procedure is pretty correctly expressed 
in the popular phrase : " It relieves the feelings." 



228 OTHER QTJASI-PEESENTATIVE ILLUSIONS. 

It is worth noting, perhaps, that these illusions of 
insight, like those of perception, may involve an in- 
attention to the actual impression of the moment. 
To erroneously attribute a feeling to another through 
an excess of sympathetic eagerness is often to over- 
look what a perfectly dispassionate observer would see, 
as, for example, the immobility of the features or the 
signs of a deliberate effort to simulate. This inatten- 
tion will, it is obvious, be greatest in the poetic attri- 
bution of life and personality to natural objects, in so 
far as this approximates to a complete momentary 
illusion. To see a dark overhanging rock as a grim 
sombre human presence, is for the moment to view it 
under this aspect only, abstracting from its many 
obvious unlikenesses. 

In the same manner, a tendency to read a particular 
meaning into a word may lead to the misapprehension 
of the word. To give an illustration : I was lately read- 
ing the fifth volume of G-. H. Lewes's Problems of 
Life and Mind. In reading the first sentence of one 
of the sections, I again and again fell into the error of 
taking "The great Lagrange," for "The great Lan- 
guage." On glancing back I saw that the section was 
headed " On Language," and I at once recognized the 
cause of my error in the pre-existence in my mind of 
the representative image of the word " language." 

In concluding this short account of the errors of 
insight, I may observe that their range is obviously 
much greater than that of the previously considered 
classes of presentative illusion. This is, indeed, in- 
volved in what has been said about the nature of the 
process. Insight, as we have seen, though here classed 



RARITY OF ACCURATE INSIGHT. 229 

with presentative cognition, occupies a kind of border- 
land between immediate knowledge or intuition and 
inference, shading off from the one to the other. And 
in the very nature of the case the scope for error 
must be great. Even overlooking human reticence, 
and, what is worse, human hypocrisy, the conditions of 
an accurate reading of others' minds are rarely realized. 
If, as has been remarked by a good authority, one 
rarely meets, even among intelligent people, with a 
fairly accurate observer of external things, what shall be 
said as to the commonly claimed power of "intuitive 
insight " into other people's thoughts and feelings, as 
though it were a process above suspicion ? It is plain, 
indeed, on a little reflection, that, taking into account 
what is required in the way of large and varied 
experience (personal and social), a habit of careful in- 
trospection, as well as a habit of subtle discriminative 
attention to the external signs of mental life, and lastly, 
a freedom from prepossession and bias, only a very few 
can ever hope even to approximate to good readers of 
character. 

And then we have to bear in mind that this large 
amount of error is apt to remain uncorrected. There is 
not, as in the case of external perception, an easy way 
of verification, by calling in another sense ; a mis- 
apprehension, once formed, is apt to remain, and I need 
hardly say that errors in these matters of mutual com- 
prehension have their palpable practical consequences. 
All social cohesion and co-operation rest on this com- 
prehension, and are limited by its degree of perfection. 
Nay, more, all common knowledge itself, in so far as it 
depends on a mutual communication of impressions, 



230 OTHER QUASI-PRESENTATIVE ILLUSIONS. 

ideas, and beliefs, is limited by the fact of this great 
liability to error in what at first seems to be one of the 
most certain kinds of knowledge. 

In view of this depressing amount of error, our 
solace must be found in the reflection that this seem- 
ingly perfect instrument of intuitive insight is, in 
reality, like that of introspection, in process of being 
fashioned. Mutual comprehension has only become 
necessary since man entered the social state, and this, 
to judge by the evolutionist's measure of time, is not so 
long ago. A mental structure so complex and delicate 
requires for its development a proportionate degree of 
exercise, and it is not reasonable to look yet for perfect 
precision of action. Nevertheless, we may hope that, 
with the advance of social development, the faculty is 
continually gaining in precision and certainty. And, 
indeed, this hope is already assured to us in the fact 
that the faculty has begun to criticise itself, to dis- 
tinguish between an erroneous and a true form of 
its operation. In fact, all that has been here said 
about illusions of insight has involved the assumption 
that intellectual culture sharpens the power and makes 
it less liable to err. 



CHAPTER X. 

ILLUSIONS OF MEMORY. 

Thus far we have been dealing with Preservative Illu- 
sions, that is to say, with the errors incident to the 
process of what may roughly be called presentative 
cognition. We have now to pass to the consideration 
of Representative Illusion, or that kind of error which 
attends representative cognition in so far as it is im- 
mediate or self-sufficient, and not consciously based on 
other cognition. Of such immediate representative 
cognition, memory forms the most conspicuous and 
most easily recognized variety. Accordingly, I pro- 
ceed to take up the subject of the Illusions of 
Memory. 1 

The mystery of memory lies in the apparent im- 
mediateness of the mind's contact with the vanished 
past. In " looking back " on our life, we seem to our- 
selves for the moment to rise above the limitations of 

1 Errors of memory have sometimes been called " fallacies," as, for 
example, by Dr. Carpenter (Human Physiology, cb. x.). While pre- 
ferring the term " illusion," I would not forget to acknowledge my 
indebtedness to Dr. Carpenter, who first set me seriously to consider 
the subject of mnemonic error. 



232 ILLUSIONS OF MEMORY. 

time, to undo its work of .extinction, seizing again the 
realities which its on-rushing stream had borne far 
from us. Memory is a kind of resurrection of the 
buried past: as we fix our retrospective glance on it, 
it appears to start anew into life ; forms arise within 
our minds which, we feel sure, must faithfully represent 
the things that were. We do not ask for any proof of 
the fidelity of this dramatic representation of our past 
history by memory. It is seen to be a faithful imita- 
tion, just because it is felt to be a revival of the past. 
To seek to make the immediate testimony of memory 
more sure seems absurd, since all our ways of de- 
scribing and illustrating this mental operation assume 
that in the very act of performing it we do recover a 
part of our seemingly " dead selves." 

To challenge the veracity of a person's memory is 
one of the boldest things one can do in the way of 
attacking deep-seated conviction. Memory is the 
peculiar domain of the individual. In going back in 
recollection to the scenes of other years he is drawing 
on the secret store-house of his own consciousness, with 
which a stranger must not intermeddle. To cast doubt 
on a person's memory is commonly resented as an im- 
pertinence, hardly less rude than to question his 
reading of his own present mental state. Even if the 
challenger professedly bases his challenge on the 
testimony of his own memory, the challenged party is 
hardly likely to allow the right of comparing testi- 
monies. He can in most cases boldly assert that those 
who differ from him are lacking in Ms power of recol- 
lection. The past, in becoming the past, has, for most 
people, ceased to be a common object of reference ; it 



IS MEMORY INFALLIBLE? 233 

has become a part of the individual's own inner self, 
and cannot be easily dislodged or shaken. 

Yet, although people in general are naturally dis- 
posed to be very confident about matters of recollec* 
tion, reflective persons are pretty sure to find out, 
sooner or later, that they occasionally fall into errors 
of memory. It is not the philosopher who first hints 
at the mendacity of memory, but the " plain man " 
who takes careful note of what really happens in the 
world of his personal experience. Thus, we hear 
persons, quite innocent of speculative doubt, qualifying 
an assertion made on personal recollection by the pro- 
viso, " unless my memory has played me false." And 
even less reflective persons, including many who pride 
themselves on their excellent memory, will, when 
sorely pressed, make a grudging admission that they 
may, after all, be in error. Perhaps the weakest de- 
gree of such an admission, and one which allows to the 
conceding party a semblance of victory, is illustrated 
in the " last word " of one who has boldly maintained a 
proposition on the strength of individual recollection, 
but begins to recognize the instability of his position : 
"I either witnessed the occurrence or dreamt it." 
This is sufficient to prove that, with all people's 
boasting about the infallibility of memory, there are 
many who have a shrewd suspicion that some of its 
asseverations will not bear a very close scrutiny. 

Psychology of Memory. 

In order to understand the errors of memory, we 
must proceed, as in the case of illusions of perception, 



234 ILLUSIONS OF MEMOET. 

by examining a little into the nature of the normal 
or correct process. 

An act of recollection is said by tko psychologist 
to be purely representative in character, whereas per- 
ception is partly representative, partly presentative. 
To recall an object to the mind is to reconstruct the 
percept in the absence of a sense-impression. 1 

An act of memory is obviously distinguished from 
one of simple imagination by the presence of a con- 
scious reference to the past. Every recollection is an 
immediate reapprehension of some past object or 
event. However vague this reference may be, it must 
be there to constitute the process one of recollection. 

The every-day usages of language do not at first 
sight seem to consistently observe this distinction. 
When a boy says, " I remember my lesson," he appears 
to be thinking of the present only, and not referring to 
the past. In truth, however, there is a vague reference 
to the fact of retaining a piece of knowledge through 
a given interval of time. 

Again, when a man says, " I recollect your face," 
this means, " Your face seems familiar to me." Here 
again, though there is no definite reference to the past, 
there is a vague and indefinite one. 

It is plain from this definition that recollection is 
involved in all recognition or identification. Merely 
to be aware that I have seen a person before implies 
a minimum exercise of memory. Yet we may roughly 
distinguish the two actions of perception and re- 
collection in the process of recognition. The mere 

1 From this it would appear to follow that, so far as a percept is 
representative, .recollection must be re-representative. 



DEFINITION OF MEMOEY. 235 

fecognition of an object does not imply the presence 
of a distinct representative or mnemonic image. In 
point of fact, in so far as recognition is assimilation, it 
cannot be said to imply a distinct act of memory at all. 
It is only when similarity is perceived amid difference, 
only when the accompaniments or surroundings of the 
object as previously seen, differencing it from the object 
as now seen, are brought up to the mind that we may 
be said distinctly to recall the past. And our state of 
mind in recognizing an object or person is commonly 
an alternation between these two acts of separating 
the mnemonic image from the percept and so recalling 
or recollecting the past, and fusing the image and the 
percept in what is specifically marked off as recog- 
nition. 1 

Although I have spoken of memory as a reinstate- 
ment in representative form of external experience, the 
term must be understood to include every revival of a 
past experience, whether external or internal, which is 
recognized as a revival. In a general way, the re- 
callings of our internal feelings take place in close 
connection with the recollection of external circum- 
stances or events, .and so they may be regarded as 
largely conditioned by the laws of this second kind of 
reproduction. 

The old conceptions of mind, which regarded every 

mental phenomenon as a manifestation of an occult 

spiritual substance, naturally led to the supposition 

that an act of recollection involves the continued, un- 

1 The relation of memory to recognition is very well discussed by 
M. Delboeuf, in connection with a definition of memory given by 
Descartes. (See the article " Le Sommeil et les Eeves," in the Revue 
PhilazopMque, April, 1SS0, p. 428, et seq.) 



236 ILLUSIONS 0F MEMORY. 

broken existence of the reproductive or mnemonic 
image in the hidden regions of the mind. To recollect 
is, according to this view, to draw the image out of 
the dark vaults of unconscious mind into the upper 
chamber of illumined consciousness. 

Modern psychology recognizes no such pigeon- 
hole apparatus in unconscious mind. On the purely 
psychical side, memory is nothing but an occasional 
reappearance of a past mental experience. And the 
sole mental conditions of this reappearance are to be 
found in the circumstances of the moment of the 
original experience and in those of the moment of 
the reappearance. 

Among these are to be specially noted, first of all, 
the degree of impressiveness of the original experience, 
that is to say, the amount of interest it awakened and 
of attention it excited. The more impressive any ex- 
perience, the greater the chances of its subsequent 
revival. Moreover, the absence of impressiveness in 
the original experience may be made good either by 
a repetition of the actual experience or, in the case 
of non-recurring experiences, by the fact of previous 
mnemonic revivals. 

In the second place, the pre-existing mental states 
at the time of revival are, essential conditions. It is 
now known that every recollection is determined by 
some link of association, that every mnemonic image 
presents itself in consciousness only when it has been 
preceded by some other mental state, presentative or 
representative, which is related to the image. This 
relation may be one of contiguity, that is to say, the 
original experiences may have occurred at the same 



PSYCHOLOGY OF MEMORY. 237 

time or in, close succession; or one of similarity 
(partial and not amounting to identity), as where the 
sight of one place or person recalls that of another 
place or person. Finally, it is to be observed that 
recollection is often an act, in the full sense of that 
term, involving an effort of voluntary attention at the 
moment of revival. 

Modern physiology has done much towards helping 
us to understand the nervous conditions of memory. 
The biologist regards memory as a special phase of 
a universal property of organic structure, namely, 
modifiability by the exercise of function, or the survival 
after any particular kind of activity of a disposition to 
act again in that particular way. The revival of a 
mental impression in the weaker form of an image is 
thus, on its physical side, due in part to this remaining 
functional disposition in the central nervous tracts con- 
cerned. And so, while on the psychical or subjective 
side we are unable to find anything permanent in 
memory, on the physical or objective side we do find 
such a permanent substratum. 

With respect to the special conditions of mne- 
monic revival at any time, physiology is less explicit. 
In a general way, it informs us that such a rein- 
statement of the past is determined by the existence 
of certain connections between the nervous struc- 
tures concerned in the reviving and revived mental 
elements. Thus, it is said that when the sound of a 
name calls up in the mind a visual image of a per- 
son seen some time since, it is because connections 
have been formed between particular regions and 
modes of activity of the auditory and the visual centres. 



238 ILLUSIONS OF MEMORY. 

And it is supposed that the existence of such connections 
is somehow due to the fact that the two regions acted 
simultaneously in the first instance, when the sight of 
the person was accompanied by the hearing of his 
name. In other words, the centres, as a whole, will tend 
to act at any future moment in the same complex way 
in which they have acted in past moments. 

All this is valuable hypothesis so far as it goes, 
though it plainly leaves much unaccounted for. As to 
why this reinstatement of a total cerebral pulsation in 
consequence of the re-excitation of a portion of the 
same should be accompanied by the specific mode of 
consciousness which we call recollection of something 
past, it is perhaps unreasonable to ask of physiology 
any sort of explanation. 1 

Thus far as to the general or essential characteristics 
of memory on its mental and its bodily side. But what 
we commonly mean by memory is, on its psychical 
side at least, much more than this. We do not say 
that we properly recollect a thing unless we are able 
to refer it to some more or less clearly defined region 
of the past, and to localize it in the succession of ex- 
periences making up our mental image of the past. 
In other words, though we may speak of an imperfect 
kind of recollection where this definite reference is 

1 A very interesting account of the most recent physiological 
theory of memory is to be found in a series of articles, bearing the title, 
" La Memoire comme fait biologique," published in the Eevue Philo- 
sophique, from the pen of the editor, M. Th. Ribot. (See especially 
the Bivue of May, 1880, pp. 516, et seq.) M. Ribot speaks of the 
modification of particular nerve-elements as " the static base " of 
memory, and of the formation of nerve-connections by means of "which 
the modified element may be re-excited to activity as " the dynamic base 
of memory " (p. 535). 



MEMORY AS LOCALIZATION. 239 

wanting, we mean by a perfect form of memory some- 
thing which, includes this reference. 

"Without entering just now upon a full analysis 
of what this reference to a particular region of the 
past means, I may observe that it takes place by help 
of an habitual retracing of the past, or certain portions 
of it, that is to say, a regressive movement of the 
imagination along the lines of our actual experience. 
Setting out from the present moment, I can move 
regressively to the preceding state of consciousness, to 
the penultimate, and so on. The fact that each distinct 
mental state is continuous with the preceding and the 
succeeding, and in a certain sense overlaps these, makes 
any portion of our experience essentially a succession 
of states of consciousness, involving some rudimentary 
idea of time. And thus, whether I anticipate a future 
event or recall a past one, my imagination, setting out 
from the present moment, constructs a sequence of 
experiences of which the one particularly dwelt on is 
the other term or boundary. And our idea of the 
position of this last in time, like that of an object in 
space, is one of a relation to our present position, 
and is determined by the length of the sequence of 
experiences thus run over by the imagination. 1 It 
may be added that since the imagination can much 
more easily follow the actual order of experience than 
conceive it as reversed, the retrospective act of 
memory naturally tends to complete itself by a return 
movement forwards from the remembered event to the 
present moment. 

1 What constitutes the difference between such a progressive and a 
retrogressive movement is a point tl at will be considered by-and-by. 



240 ILLUSIONS OF MEMORY. 

In practice this detailed retracing of successive 
moments of mental life is confined, to very recent 
experiences. If I try to localize in time a remote 
event, I am content with placing it in relation to a 
series of prominent events or landmarks which serves 
me as a rough scheme of the past. The formation 
of such a mnemonic framework is largely due to the 
needs of social converse, which proceeds by help of a 
common standard of reference. This standard is sup- 
plied by those objective, that is to say, commonly ex- 
perienced regularities of succession which constitute 
the natural and artificial divisions of the years, seasons, 
months, weeks, etc. The habit of recurring to these 
fixed divisional points of the past renders a return 
of imagination to any one of them more and more 
easy. A man has a definite idea of " a year ago " 
which the child wants, just because he has had so fre- 
quently to execute that vague regressive movement 
by which the idea arises. And though, as our actual 
point in time moves forward, the relative position of 
any given landmark is continually changing, the 
change easily adapts itself to that scheme of time- 
divisions which holds good for any present point. 

Few of our recollections of remote events involve 
a definite reference to this system of landmarks. 
The recollections of early life are, in the case of 
most people, so far as they depend on individual 
memory, very vaguely and. imperfectly localized. And 
many recent experiences which are said to be half 
forgotten, are not referred to any clearly assignable 
position in time. One may say that in average cases 
definite localization characterizes only such supremely 



IMPERFECT MNEMONIC LOCALIZATION. 241 

interesting personal experiences as spontaneously recur 
again and again to the mind. For the rest it is con- 
fined to those facts and events of general interest to 
which our social habits lead us repeatedly to go back. 1 

The consciousness of personal identity is said to be 
bound up with memory. That is to say, I am conscious 
of a continuous permanent self under all the varying 
surface-play of the stream of consciousness, just because 
I can, by an act of recollection, bring together any 
two portions of this stream of experience, and so 
recognize the unbroken continuity of the whole. If 
this is so, it would seem to follow from the very frag- 
mentary character of our recollections that our sense 
of identity is very incomplete. As we shall see 
presently, there is good reason to look upon this 
consciousness of continuous personal existence as rest- 
ing only in part on memory, and mainly on our inde- 
pendently formed representation of what has happened 
in the numberless and often huge lacunae of the past 
left by memory. 

Having thus a rough idea of the mechanism of 
memory to guide us, we may be able to investigate 
the illusions incident to the process. 

Illusions of Memory. 

By an illusion of memory we are to understand a 
false recollection or a wrong reference of an idea to 

1 It is not easy to say how far exceptional conditions may serve to 
reinstate the seemingly forgotten past. Yet the experiences of dreamers 
and of those "who have been recalled to consciousness after partial 
drowning, whatever they may prove 'with respect to the revivability of 
remote experiences, do not lead us to imagine that the range of our 
definitely localizing memory is a wide one. 



242 ILLUSIONS OF MEMORY. 

some region of the past. It might, perhaps, be roughly 
described as a wrong interpretation of a special kind 
of mental image, namely, what I have called a 
mnemonic image. 

Mnemonic illusion is thus distinct from mere forget- 
fulness or imperfect memory. To forget or be doubt- 
ful about a past event is one thing ; to seem to ourselves 
to remember it when we afterwards find that the fact 
was otherwise than we represented it in the apparent 
act of recollection is another thing. Indistinctness of 
recollection, or the decay of memory, is, as we shall 
soon see, an important co-operant condition of mnemonic 
illusion, but does not constitute it, any more than 
haziness of vision or disease of the visual organ, though 
highly favourable to optical illusion, can be said to 
constitute it. 

We may conveniently proceed in our detailed 
examination of illusions of memory, by distinguishing 
between three facts which appear to be involved in 
every complete and accurate process of recollection. 
When I distinctly recall an event, I am immediately sure 
of three things : (1) that something did really happen 
to me ; (2) that it happened in the way I now think ; 
and (3) that it happened when it appears to have 
happened. I cannot be said to recall a past event 
unless I feel sure on each of these points. Thus, to be 
able to say that an event happened at a particular 
date, and yet unable to describe how it happened, 
means that I have a very incomplete recollection. 
The same is true when I can recall an event pretty 
distinctly, but fail to assign it its proper date. This 
being so, it follows that there are three possible open- 



ILLUSIONS CLASSIFIED. 243 

ings, and only three, by which errors of memory may 
creep in. And, as a matter of fact, each of these open- 
ings will be found to let in one class of mnemonic 
illusion. Thus we have (1) false recollections, to 
which there correspond no real events of personal 
history; (2) others which misrepresent the manner of 
happening of the events ; and (3) others which falsify 
the date of the events remembered. 

It is obvious, from a mere glance at this three- 
fold classification, that illusions of memory closely 
correspond to visual illusions. Thus, class (1) may be 
likened to the optical illusions known as subjective 
sensations of light, or ocular spectra. Here we can 
prove that there is nothing actually seen in the field 
of vision, and that the semblance of a visible object 
arises from quite another source than that of ordinary 
external light-stimulation, and by what may be called 
an accident. Similarly, in the case of the first class of 
mnemonic illusions, we shall find that there is nothing 
actually recollected, but that the mnemonic spectra or 
phantoms of recollected objects can be accounted for 
in quite another way. Such illusions come nearest to 
hallucinations in the region of memory. 

Again, class (2) has its visual analogue in those 
optical illusions which depend on effects of haziness and 
of the action of refracting media interposed between the 
eye and the object ; in which cases, though there is 
some real thing corresponding to the perception, this 
is seen in a highly defective, distorted, and misleading 
form. In like manner, we can say that the images of 
memory often get obscured, distorted, and otherwise 
altered when they have receded into the dim distance, 



244 ILLUSIONS OF MEMORY. 

and are looked back upon through a long space of 
intervening mental experience. Finally, class (3) has 
its visual counterpart in erroneous perceptions of dis- 
tance, as when, for example, owing to the clearness of 
the mountain atmosphere and the absence of inter- 
vening objects, the side of the Jungfrau looks to the 
inexperienced tourist at Wengernalp hardly further 
than a stone's throw. It will be found that when our 
memory falsifies the date of an event, the error arises 
much in the same way as a visual miscalculation of 
distance. 

This threefold division of illusions of memory is 
plainly a rather superficial one, and not based on dis- 
tinctions of psychological nature or origin. In order to 
make our treatment of the subject scientific as well as 
popular, it will be necessary to introduce the distinction 
between the passive and the active factor under each 
head. It will be found, I think, without forcing the 
analogy too far, that here, as in the case of the illusions 
of perception and introspection, error is attributable 
now to misleading suggestion on the part of the mental 
content of the moment, now to a process of incorpo- 
rating into this content a mental image not suggested 
by it, but existing independently. 

If we are to proceed as we did in the case of the 
illusions of sense, and take up the lower stages of error 
first of all, we shall need to begin with the third 
class of errors, those of localization in time, or of what 
may be called mnemonic perspective. It has been 
already observed that the definite localization of a 
mnemonic image is only an occasional accompaniment 
of what is lcosely called recollection. Hence, error as 



ILLUSIONS OF TIME-PEKSPECTIYE. 245 

to the position of an event in the past chain of events 
would seem to involve the least degree of violation 
of the confidence which we ' are wont to repose in 
memory. After this, we may proceed to the discussion 
of the second class, which I may call distortions of the 
mnemonic picture. And, finally, we may deal with 
the most signal and palpable variety of error of memory, 
namely, the illusions which I have called mnemonic 
spectra. 

Illusions of Perspective : A. Definite Localization. 

In order to understand these errors of mnemonic 
perspective, we shall have to inquire more closely than 
we have yet done into the circumstances which cus- 
tomarily determine our idea of the degree of propin- 
quity or of remoteness of a past event. And first of 
all, we will take the case of a complete act of recollec- 
tion when the mind is able to travel back along an 
uninterrupted series of experiences to a definitely 
apprehended point. Here there would seem, at first 
sight, to be no room for error, since this movement 
of retrospective imagination may be said to involve 
a direct measurement of the distance, just as a sweep 
of the eye over the ground between a spectator and an 
object affords a direct measurement of the intervening 
space. 

Modern science, however, tells us that this mode of 
measurement is by no means the simple and accurate 
process which it at first seems to be. In point of fact, 
there is something like a constant error in all such 
retrospective measurement. Vierordt has proved ex- 
perimentally, by making a person try to reproduce the 



216 ILLUSIONS OE MEMOEY. 

varying time- intervals between the strokes of the 
pendulum of a metronome, that when the interval is 
a very small one, we uniformly tend to exaggerate it 
in retrospection ; when a large one, to regard it, on 
the contrary, as less than it actually was. 1 

A mere act of reflection will convince any one that 
when he tries to conceive a very small interval, say a 
quarter of a second, he is likely to make it too great. 
On the other hand, when we try to conceive a year, we 
do not fully grasp the whole extent of the duration. 
This is proved by the fact that merely by spending 
more time over the attempt, and so recalling a larger 
number of the details of the period, we very consider- 
ably enlarge our first estimate of the duration. And 
this leads to great discrepancies in the appreciation of 
the relative magnitudes of past sections of time. Thus, 
as Wundt observes, though in retrospect both a month 
and a year seem too short, the latter is relatively much 
more shortened than the former. 2 

The cause of this constant error in the mode of 
reproducing durations seems to be connected with the 
very nature of the reproductive act. It must be borne 
in mind that this act is itself, like the experience which 
it represents, a mental process, occupying time, and that 
consequently it may very possibly reflect its time- 
character on the resulting judgment. Thus, since it 
certainly takes more than a quarter of a second to pass 
in imagination from one impression to another, it may 
be that we tend to confound this duration with that 
which we try to represent. Similarly, the fact that 

1 Der Zeitsinn nach Yersuclien, p. 36, et seq. 
8 Physiologisehe Psychologie, p. 782. 



MISEEPEESENTATION OF PAST TIME. 247 

in the act of reproductive imagination we under-esti- 
mate a longer interval between two impressions, say 
those of the slow beats of a colliery engine, may be 
accounted for by the supposition that the imagination 
tends to pass from the one impression to the succeed- 
ing one too rapidly. 1 

The gross misappreciation of duration of long 
periods of time, while it may illustrate the principle 
just touched on, clearly involves the effect of other 
and more powerful influences. A mere glance at what 
is in our mind when we recall such a period as a 
month or a year, shows that there is no clear concrete 
representation at all. Time, it has been often said, is 
known only so far as rilled with concrete contents or 
conscious experiences, and a perfect imagination of any 
particular period of past time would involve a re- 
tracing of all the successive experiences which have 
gone to make up this section of our life. This, I need 
not say, never happens, both because, on the one hand, 
memory does not allow of a complete reproduction of 
any segment of our experience, and because, on the 
other hand, such an imaginative reproduction, even if 
possible, would clearly occupy as much time as the 
experience itself. 2 

1 Wundt refers these errors to variations in the state of pre-adjust- 
ment of the attention to impressions and representations, according 
as they succeed one another slowly or rapidly. There is little donbt 
that the effects of the state of tension of the apparatus of attention are 
involved here, though I am disposed to think that Wundt makes too 
much of this circumstance. (See Physiologisclie Psychologie, pp. 7S2, 
783. I have given a fuller account of Wundt's theory in Mind, No. i.) 

2 Strictly speaking, it would occupy more time, since the effort 
of recalling each successive link in the chain would involve a greater 
interval between any two images than that between the corresponding 
experiences. 



248 ILLUSIONS OF MEMOKY. 

When I call up an image of the year just closing, 
what really happens is a rapid movement of imagination 
over a series of prominent events, among which the 
succession of seasons probably occupies the foremost 
place, serving, as I have remarked, as a framework for 
my retrospective picture. Each of the events which I 
thus run over is really a long succession of shorter 
experiences, which, however, I do not separately repre- 
sent to myself. My imaginative reproduction of such 
a period is thus essentially a greatly abbreviated and 
symbolic mode of representation. It by no means 
corresponds to the visual imagination of a large mag- 
nitude, say that of the length of sea horizon visible at 
any one moment, which is complete in an instant, and 
quite independent of a successive imagination of its 
parts or details. It is essentially a very fragmentary 
and defective numerical idea, in which, moreover, the 
real quantitative value of the units is altogether lost 
sight of. 

Now, it seems to follow from this that there is 
something illusory in all our recallings of long periods 
of the past. It is by no means strictly correct to say 
that memory ever reinstates the past. It is more true 
to say that we see the past in retrospect as greatly 
foreshortened. Yet even this is hardly an accurate 
account of Avhat takes place, since, when we look at an 
object foreshortened in perspective, we see enough to 
enable us imaginatively to reconstruct the actual size 
of the object, whereas in the case of time-perspective 
no such reconstruction is even indirectly possible. 

It is to be added that this constant error in time- 
reproduction is greater in the case of remote periods 



ABSOLUTE AND EELATIVE DUKATION. 2 AD 

than of near ones of the same length. Thus, the retro- 
spective estimate of a duration far removed from the 
present, say the length of time passed at a particular 
school, is much more superficial and fragmentary than 
that of a recent corresponding period. So that thy 
time-vista of the past is seen to answer pretty closely 
to a visible perspective in which the amount of ap- 
parent error due to foreshortening increases with the 
distance. 

In practice, however, this defect in the imagina- 
tion of duration leads to no error. Although, as a 
concrete image answering to some definite succession 
of experiences a year is a gross misrepresentation, as a 
general concept implying a collection of a certain 
number of similar successions of experience it is suffi- 
ciently exact. That is to say, though we cannot 
imagine the absolute duration of any such cycle of 
experience, we can, by the simple device of conceiving 
certain durations as multiples of others, perfectly well 
compare different periods of times, and so appreciate 
their relative magnitudes. 

Leaving, then, this constant error in time-appre- 
ciation, we will pass to the variable and more palpable 
errors in the retrospective measurement of time. Each 
person's experience will have told him that in esti- 
mating the distance of a past event by a mere retro- 
spective sense of duration, he is liable to extraordinary 
fluctuations of judgment. Sometimes when the clock 
strikes we are surprised at the rapidity of the hour. 
At other times the timepiece seems rather to have 
lagged behind its usual pace. And what is true of a 
short interval is still more true of longer intervals, as 

JL/w 



250 ILLUSIONS OF MEMORY. 

months and years. The understanding of these fluc- 
tuations will be promoted by our brief glance at the 
constant errors in retrospective time-appreciation. 

And here it is necessary to distinguish between the 
sense of duration which we have during any period, 
and the retrospective sense which survives the period, 
for these do not necessarily agree. The former rests 
mainly on our prospective sense of time, whereas the 
latter must be altogether retrospective. 1 

Our estimate of time as it passes is commonly said 
to depend on the amount of consciousness which we 
are giving to the fact of its transition. Thus, when 
the mind is unoccupied and suffering from ennui, we 
feel time to move sluggishly. On the other hand, 
interesting employment, by diverting the thoughts from 
time, makes it appear to move at a more rapid pace. 
This fact is shown in the common expressions which 
we employ, such as " to kill time," and the German 
Langweile. Similarly, it is said that when we are 
eagerly anticipating an event, as the arrival of a friend, 
the mere fact of dwelling on the interval makes it 
appear to swell out. 2 

This view is correct in the main, and is seen, indeed, 
to follow from the great psychological principle that 
what we attend to exists for us more, has more reality, 
and so naturally seems greater than what we do not 

1 I need hardly say that there is no sharp distinction between these 
two modes of subjective appreciation. Our estimate of an interval as 
it passes is really made up of a number of renewed anticipations and 
recollections of the successive experiences. Yet we can say broadly 
that this is a prospective estimate, while that which is formed when 
the period has quite expired must be altogether retrospective. 

2 See an interesting paper on " Consciousness oi Time," by Mr. G. 
J. Romanes, in Mind (July, 187S). 



ESTIMATE OF DURATION AT THE TIME. 251 

attend to. At the same time, this principle must be 
supplemented by another consideration. Suppose that 
I am very desirous that time should not pass quickly. 
If, for example, I am enjoying myself or indulging in 
idleness, and know that I have to be off to keep a not 
very agreeable engagement in a quarter of an hour, 
time will seem to pass too rapidly ; and this not be- 
cause my thoughts are diverted from the fact of its 
transition, for, on the contrary, they are reverting to it 
more than they usually do, but because my wish to 
lengthen the interval leads me to represent the un- 
welcome moment as further off than it actually is, in 
other words, to construct an ideal representation of 
the period in contrast with which the real duration 
looks miserably short. 

Our estimate of duration, when it is over, depends 
less on this circumstance of having attended to its 
transition than on other considerations. Wundt, in- 
deed, seems to think that the feeling accompanying 
the actual flow of time has no effect on the surviving 
subjective appreciation ; but this must surely be an 
error, since our mental image of any period is deter- 
termined by the character of its contents. Wundt 
says that when once a tedious waiting is over, it looks 
short because we instantly forget the feeling of tedium. 
My self-observation, as well as the interrogation of 
others, has satisfied me, on the contrary, that this 
feeling distinctly colours the retrospective apprecia- 
tion. Thus, when waiting at a railway station for a be- 
lated train, I am distinc tly aware that each quarter of 
an hour looks long, not only as it passes, but when it 
is over. In fact, I am disposed to express my feeling 



252 ILLUSIONS OF MEMORY. 

as one of disappointment that only so short an interval 
has passed since I last looked at my watch. 

Nevertheless, I am ready to allow that, though a 
feeling of tedium, or the contrary feeling of irritation 
at the rapidity of time, will linger for an appreciable 
interval and colour the retrospective estimate of time, 
this backward view is chiefly determined by other con- 
siderations. As Wundt remarks, we have no sense of 
time's slowness during sleep, yet on waking we imagine 
that we have been dreaming for an immensely long 
period. This retrospective appreciation is determined 
by the number and the degree or intensity of the 
experiences, and, what comes very much to the same 
thing, by the amount of unlikeness, freshness, and dis- 
continuity characterizing these experiences. 

Time, as I have already hinted, is known under the 
form of a succession of different conscious experiences. 
Unbroken uniformity would give us no sense of time, 
because it would give us no conscious experience at 
all. Strictly speaking, there is no such thing as a 
perfectly uniform mental state extending through an 
appreciable duration. In looking at one and the same 
object, even in listening to one and the same tone, I 
am in no two successive fractions of a second in exactly 
the same state of mind. Slight alterations in the 
strength of the sensation, 1 in the degree or direction of 
attention, and in the composition of that penumbra 
of vague images which it calls up, occur at every dis- 
tinguishable fraction of time. 

1 It is well known that there is, from the first, a gradual falling 
off in the strength of a sensation of light when a moderately bright 
object is looked at 



ESTIMATE OF DTJEATION AFTEEWAEDS 253 

This being so, it would seem to follow that the 
greater the number of clearly marked changes, and 
the more impressive and exciting these transitions, the 
fuller will be our sense of time. And this is borno 
out by individual reflection. When striking and deeply 
interesting events follow one another very rapidly, as 
when we are travelling, duration appears to swell 
out. 

It is possible that such a succession of stirring ex- 
periences may beget a vague consciousness of time at 
each successive moment, and apart from retrospection, 
simply by force of the change. In other words, without 
our distinctly attending to time, a series of novel im- 
pressions might, by giving us the consciousness of 
change, make us dimly aware of the numerical richness 
of our experiences. But, however this be, there is no 
doubt that, in glancing back on such a succession of 
exciting transitions of mental condition, time appears 
to expand enormously, just as it does in looking back 
on our dream-experience, or that rapid series of in- 
tensified feelings which, according to De Quincey and 
others, is produced by certain narcotics. 

The reason of this is plain. Such a type of succes- 
sive experience offers to the retrospective imagination 
a large number of distinguishable points, and since this 
mode of estimating time depends, as we have seen, on 
the extent of the process of filling in, time will neces- 
sarily appear long in this case. On the other hand, 
when we have been engaged in very ordinary pursuits, 
in which few deeply interesting or exciting events 
have impressed themselves on memory, our retrospec- 
tive picture will necessarily be very much of a blank, 



254 ILLUSIONS OF MEMORY. 

and consequently the duration of the period will seem 
to be short. 

I observed that this retrospective appreciation of 
time depended on the degree of connection between 
the successive experiences. This condition is very- 
much the same as the other just given, namely, the 
degree of uniformity of the experiences, since the more 
closely the successive stages of the experience are 
connected — as when, for example, we are going through 
our daily routine of work — the more quiet and un- 
exciting will be the transition from each stage to its 
succeeding one. And on the other hand, all novelty of 
impression and exciting transition of experience clearly 
involves a want of connection. Wundt thinks the 
retrospective estimate of a connected series of expe- 
riences, such as those of our daily round of occupa- 
tions, is defective just because the effort of attention, 
which precedes even an imaginative reproduction of 
an impression, so quickly accommodates itself in this 
case to each of the successive steps, whereas, when the 
experiences to be recalled are disconnected, the effort 
requires more time. In this way, the estimate of a 
past duration would be coloured by the sense of time 
accompanying the reproductive process itself. This 
may very likely be the case, yet I should be disposed 
to attach most importance to the number of distin- 
guishable items of experience recalled. 

Our representation of the position of a given event 
in the past is, as I have tried to show, determined by 
the movement of imagination in going back to it from 
the present. And this is the same thing as to say 
that it depends on our retrospective sense of the inter- 



VABIATIONS IN TIME-ESTIMATE. 255 

veiling space. That is to say, the sense of distance in 
time, as in space, is the recognition of a term to a 
movement. And just as the distance of an object will 
seem greater when there are many intervening objects 
affording points of measurement, than when there are 
none (as on the uniform surface of the sea), so the 
distance of an event will vary with the number of 
recognized intervening points. 

The appreciation of the distance of an event in time 
does not, however, wholly depend on the character of 
this movement of imagination. Just as the apparent 
distance of a visible object depends inter alia, on the 
distinctness of the retinal impression, so the apparent 
temporal remoteness of a past event depends in part 
on the degree of intensity and clearness of the mne- 
monic image. This is seen even in the case of those 
images which we are able distinctly to localize in the 
time-perspective. For a series of exciting experiences 
intervening between the present and a past event ap- 
pears not only directly to add to our sense of distance by 
constituting an apparently long interval, but indirectly 
to add to it by giving an unusual degree of faintness 
to the recalled image. An event preceding some un- 
usually stirring series of experiences gets thrust out 
of consciousness by the very engrossing nature of the 
new experiences, and so tends to grow more faint and 
ghost-like than it would otherwise have done. 

The full force of this circumstance is best seen in 
the fact that a very recent event, bringing with it a 
deep mental shock and a rapid stirring of wide tracts of 
feeling and thought, may get to look old in a marvel- 
lously short space of time. An announcement of the 



256 ILLUSIONS OF MEMORY. 

loss of a dear friend, when sudden and deeply agitating, 
will seem remote even after an hour of such intense 
emotional experience. And the same twofold con- 
sideration probably explains the well-known fact that 
a year seems much shorter to the adult than to the 
child. The novel and comparatively exciting im- 
pressions of childhood tend to fill out time in retro- 
spect, and also to throw back remote events into a 
dimly discernible region. 

Now, this same circumstance, the degree of vivid- 
ness or of faintness of the mnemonic image, is that 
which determines our idea of distance when the 
character of the intervening experiences produces no 
appreciable effect. 1 This is most strikingly illus- 
trated in those imperfect kinds of recollection in which 
we are unable to definitely localize the mnemonic 
image. To the consideration of these we will now 
turn. 

B. Indefinite Localization. 

Speaking roughly and generally, we may say that 
the vividness of an image of memory decreases in pro- 
portion as the distance of the event increases. And 
this is the rule which we unconsciously apply in 
determining distance in time. Nevertheless, this rule 
gives us by no means an infallible criterion of distance. 
The very fact that different people so often dispute 
about the dates and the order of past events experienced 
in common, shows pretty plainly that images of the 

1 Cf. Hartley, Observations on Man, Part I. ch. iii. sec. 4 (fifth edit., 
p. 391). 



EFFECT OF VIVIDNESS OF EECOLLECTION. 257 

same age tend to arise in the mind with, very unequal 
degrees of vividness. 

Sometimes pictures of very remote incidents may 
suddenly present themselves to our minds with a 
singular degree of brightness and force. And when 
this is the case, there is a disposition to think of 
them as near. If the relations of the event to other 
events preceding and succeeding it are not remem- 
bered, this momentary illusion will persist. We have 
all heard persons exclaim, "It seems only yester- 
day," under the sense of nearness which accompanies 
a recollection of a remote event when vividly excited. 
The most familiar instance of such lively reproduction 
is the feeling which we experience on revisiting the 
scene of some memorable event. At such a time the 
past may return with something of the insistence of a 
present perceived reality. In passing from place to 
place, in talking with others, and in reading, we are 
liable to the sudden return by hidden paths of associa- 
tion of images of incidents that had long seemed 
forgotten, and when they thus start up fresh and 
vigorous, away from their proper surroundings, they 
invariably induce a feeling of the propinquity of the 
events. 

In many cases we cannot say why these particular 
images, long buried in oblivion, should thus suddenly 
regain so much vitality. There seems, indeed, to be 
almost as much that is arbitrary and capricious in the 
selection by memory of its vivid images as in the 
selection of its images as a whole ; and, this being so, 
it is plain that we are greatly exposed to the risk of 
illusion from this source. 



258 ILLUSIONS OF MEMORY. 

There is an opposite effect in the case of recent 
occurrences that, for some reason or another, have 
left but a faint impression on the memory ; though 
this fact is not, perhaps, so familiar as the other. I 
met a friend, we will suppose, a few days since at my 
club, and we exchanged a few words. My mind was 
somewhat preoccupied at the time, and the occurrence 
did not stamp itself on my recollection. To-day I 
meet him again, and he reminds me of a promise 
I made him at the time. His reminder suffices to 
restore a dim image of the incident, but the fact 
of its dimness leads to the illusion that it really 
happened much longer ago, and it is only on my 
friend's strong assurances, and on reasoning from other 
data that it must have occurred the day he mentions, 
that I am able to dismiss the illusion. 

The most striking examples of the illusory effect 
of mere vividness, involving a complete detachment 
of the event from the prominent landmarks of the 
past, are afforded by public events which lie outside 
the narrower circle of our personal life, and which do 
not in the natural course of things become linked to 
any definitely localized points in the field of memory. 
These events may be very stirring and engrossing 
for the time, but in many cases they pass out of the 
mind just as suddenly as they entered it. We have 
no occasion to revert to them, and if by chance we are 
afterwards reminded of them, they are pretty certain 
to look too near, just because the fact of their having 
greatly interested us has served to render their images 
particularly vivid. 

A curious instance of this illusory effect was 



ISOLATED PUBLIC EVENTS. 259 

supplied not long since by the case of the ex-de- 
tectives, the expiration of whose term of punishment 
(three years) served as an occasion for the newspapers 
to recall the event of their trial and conviction. The 
news that three years had elapsed since this well- 
remembered occurrence proved very startling to myself, 
and to a number of my friends, all of us agreeing that 
the event did not seem to be at more than a third of its 
real distance. More than one newspaper commented 
on the apparent rapidity of the time, and this shows 
pretty plainly that there was some cause at work, such 
as I have suggested, producing a common illusion. 

I have treated of these illusions connected with the 
estimate of past time and the dating of past events as 
passive illusions, not involving a,uy active predisposi- 
tion on the part of the imagination. At the same 
time, it is possible that error in these matters may occa- 
sionally depend on a present condition of the feelings 
and the imagination. It seems plain that since the 
apparent degree of remoteness of an event not distinctly 
localized in the past varies inversely as the degree of 
vividness of the mnemonic image, any conscious con- 
centration of mind on a recollection will tend to bring 
it too near. In this way, then, an illusory propinquity 
may be given to a recalled event through a mere 
desire to dwell on it, or even a capricious wish to 
deceive one's self. 

When, for example, old friends come together and 
talk over the days of yore, there is a gradual reinstate- 
ment of seemingly lost experiences, which often partakes 
of the character of a semi-voluntary process of self- 
delusion. Through the cumulative effect of mutual 



260 ILLUSIONS OF MEMOEY. 

reminder, incident after incident returns, adding some- 
thing to the whole picture till it acquires a degree of 
completeness, coherence, and vividness that render it 
hardly distinguishable from a very recent experience. 
The process is like looking at a distant object through 
a field-glass. Mistiness disappears, fresh details come 
into view, till we seem to ourselves to be almost within 
reach of the object. 

Where the mind habitually goes back to some 
painful circumstance under the impulse of a morbid 
disposition to nurse regret, this momentary illusion 
may become recurring, and amount to a partial coo- 
fusion of the near and the remote in our experience. 
An injury long brooded on seems at length a thing 
that continually moves forward as we move ; it always 
presents itself to our memories as a very recent event. 
In states of insanity brought on by some great shock, 
we see this morbid tendency to resuscitate the dead 
past fully developed, and remote events and circum- 
stances becoming confused with present ones. 

On the other hand, in more healthy states of mind 
there presents itself an exactly opposite tendency, 
namely, an impulse of the will to banish whatever 
when recalled gives pain to the furthest conceivable 
regions of the past. Thus, when we have lost some- 
thing we cherished dearly, and the recollection of it 
brings fruitless longing, we instinctively seek to expel 
the recollection from our minds. The very feeling 
that what has been can never again be, seems to induce 
this idea of a vast remoteness of the vanished reality. 
When, moreover, the lost object was fitted to call forth 
the emotion of reverence, the impulse to magnify the 



CHERISHING AND BANISHING THE PAST. 261 

Temoteness of the loss may not improbably be rein- 
forced by the circumstance that everything belonging 
to the distant past is fitted on that account to excite 
a feeling akin to reverence. So, again, any rupture in 
our mental development may lead us to exaggerate 
the distance of some past portion of our experience. 
When we have broken with our former selves, either in 
the way of worsening or bettering, we tend to project 
these further into the past. 

It is only when the sting of the recollection is 
removed, when, for example, the calling up of the 
image of a lost friend is no longer accompanied with 
the bitterness of futile longing, that a healthy mind 
ventures to nourish recollections of such remote events 
and to view these as part of its recent experiences. 
In this case the mnemonic image becomes transformed 
into a kind of present emotional possession, an element 
of that idealized and sublimated portion of our ex- 
perience with which all imaginative persons fill up 
the emptiness of their actual lives, and to which the 
poet is wont to give an objective embodiment in his 
verse. 

Distortions of Memory. 
It is now time to pass to the second group of 
illusions of memory, which, according to the analogy 
of visual errors, may be called atmospheric illusions. 
Here the degree of error is greater than in the case of 
illusions of time-perspective, since the very nature of 
the events or circumstances is misconceived. We do 
not recall the event as it happened, but see it in part 
only, and obscured, or bent and distorted as by a 



262 ILLUSIONS OF MEMORY. 

process of refraction. Indeed, this transformation of 
the past does closely correspond with the transforma- 
tion of a visible object effected by intervening media. 
Our minds are such refracting media, and the past 
reappears to us not as it actually was when it was close 
to us, but in numerous ways altered and disguised by 
the intervening spaces of our conscious experience. 

To begin with, what we call recollection is uniformly 
a process of softening the reality. When we appear to 
ourselves to realize events of the remote past, it is 
plain that our representation in a general way falls 
below the reality : the vividness, the intensity of our 
impressions disappears. More particularly, so far as 
our experiences are emotional, they tend thus to be- 
come toned down by the mere lapse of time and the 
imperfections of our reproductive power. That which 
we seem to see in the act of recollection is thus very 
different from the reality. 

Not only is there this general deficiency in 
mnemonic representation, there are special deficiencies 
due to the fact of oblivescence. Our memories restore 
us only fragments of our past life. And just as objects 
seen imperfectly at a great distance may assume a 
shape quite unlike their real one, so an inadequate 
representation of a past event by memory often amounts 
to misrepresentation. When revisiting a place that 
we have not seen for many years, we are apt to find 
that our recollection of it consisted only of some in- 
significant details, which arranged themselves in our 
minds into something oddly unlike the actual scene 
So, too, some accidental accompaniment of an incident 
in early life is preserved, as though it were the main 



FORGETFULNESS AND EEROR. 263 

feature, serving to give quite a false colouring to the 
whole occurrence. 

It seems quite impossible to account for these 
particular survivals, they appear to be so capricious. 
When a little time has elapsed after an event, and 
the attendant circumstances fade away from memory, 
it is often difficult to say why we were impressed 
with it as we afterwards prove to have been. It is 
no doubt possible to see that many of the recollections 
of our childhood owe their vividness to the fact of 
the exceptional character of the events ; but this can- 
not always be recognized. Some of them seem to our 
mature minds very oddly selected, although no doubt 
there are in every case good reasons, if we could 
only discover them, why those particular incidents 
rather than any others should have been retained. 

The liability to error resulting from mere obliv- 
escence and the arbitrary selection of mental images is 
seen most plainly, perhaps, in our subsequent represen- 
tation and estimate of whole periods of early life. Our 
idea of any stage of our past history, as early child- 
hood, or school days, is built up out of a few fragmentary 
intellectual relics which cannot be certainly known to 
answer to the most important and predominant experi- 
ences of the time. When, for example, we try to decide 
whether our school days were our happiest days, as is 
so often alleged, it is obvious that we are liable to fall 
into illusion through the inadequacy of memory to pre- 
serve characteristic or typical features, and none but 
these. We cannot easily recall the ordinary every-day 
level of feeling of a distant period of life, but rather 
think of exceptional moments of rejoicing or depression. 



264 ILLUSIONS OF MEMOKY. 

The ordinary man's idea of the emotional experience of 
his school days is probably built up out of a few scrappy 
recollections of extraordinary and exciting events, such 
as unexpected holidays, success in the winning of 
prizes, famous " rows " with the masters, and so on. 

Besides the impossibility of getting at the average 
and prevailing mental tone of a distant section of life, 
there is a special difficulty in determining the degree 
of happiness of the past, arising from the fact that our 
memory for pleasures and for pains may not be equally 
good. Most people, perhaps, can recall the enjoyments 
of the past much more vividly than the sufferings. 
On the other hand, there seem to be some who find 
the retention of the latter the easier of the two. This 
fact should not be forgotten in reading the narrative 
of early hardships which some recent autobiographies 
have given us. 

Not only does our idea of the past become inexact 
by the mere decay and disappearance of essential 
features, it becomes positively incorrect through the 
gradual incorporation of elements that do not properly 
belong to it. Sometimes it is easy to see how these 
extraneous ideas get imported into our mental repre- 
sentation of a past event. Suppose, for example, that 
a man has lost a valuable scarf-pin. His wife suggests 
that a particular servant, whose reputation does not 
stand too high, has stolen it. When he afterwards 
recalls the loss, the chances are that he will confuse 
the fact with the conjecture attached to it, and say he 
remembers that this particular servant did steal the 
pin. Thus, the past activity of imagination serves to 
corrupt and partially falsify recollections that have a 
genuine basis of fact. 



CONFUSION OF MNEMONIC ELEMENTS. 265 

It is evident that this class of mnemonic illusions 
approximates in character to illusions of perception. 
When the imagination- supplies the interpretation at 
the very time, and the mind reads this into the per- 
ceived object, the error is one of perception. "When 
the addition is made afterwards, on reflecting upon the 
perception, the error is one of memory. The " fallacies 
of testimony " which depend on an adulteration of pure 
observation with inference and conjecture, as, for 
example, the inaccurate and wild statements of people 
respecting their experiences at spiritualist seances, 
while they illustrate the curious blending of both 
kinds of error, are probably much oftener illusions of 
memory than of perception. 1 

Although in many cases we can account to ourselves 
for this confusion of fact and imagination, in other 
cases it is difficult to see any close relation between 
the fact remembered and the foreign element imported 
into it. An idea of memory seems sometimes to lose 
its proper moorings, so to speak ; to drift about help- 
lessly among other ideas, and finally, by some chance, 
to hook itself on to one of these, as though it naturally 
belonged to it. Anybody who has had an opportunity 
of carefully testing the truthfulness of his recollection 
of some remote event in early life will have found how 
oddly extraneous elements become incorporated into 
the memorial picture. Incidents get put into wrong 
places, the wrong persons are introduced into a scene, 
and so on. Here again we may illustrate the mne- 
monic illusion by a visual one. When a tree standing 
before or behind a house and projecting above or to 

1 See Dr. Carpenter's Mental Physiology, fourth edit., p. 456. 



266 ILLUSIONS OF MEMOEY. 

the side of it is not sharply distinguished from the 
latter, it may serve to give it a very odd appearance. 

These confusions of the mental image may arise even 
when only a short interval has elapsed. In the case of 
many of the fleeting impressions that are only half 
recollected, this kind of error is very easy. Thus, for 
example, I may have lent a book to a friend last week. 
I really remember the act of lending it, but have 
forgotten the person. But I am not aware of this. 
The picture of memory has unknowingly to myself 
been filled up by this unconscious process of shifting 
and rearrangement, and the idea of another person has 
by some odd accident got substituted for that of the 
real borrower. If we could go deeply enough into the 
matter, we should, of course, be able to explain why this 
particular confusion arose. We might find, for ex- 
ample, that the two persons were associated in my 
mind by a link of resemblance, or that I had 
dealings with the other person about the same time. 
Similarly, when we manage to join an event to a wrong 
place, we may find that it is because we heard of the 
occurrence when staying at the particular locality, or 
in some other way had the image of the place closely 
associated in our minds with the event. But often we 
are wholly unable to explain the displacement. 

So far I have been speaking of the passive pro- 
cesses by which the past comes to wear a new face to 
our imaginations. In these our present habits of feeling 
and thinking take no part ; all is the work of the past, 
of the decay of memory, and the gradual confusion of 
images. This process of disorganization may be 
likened to the action of damp on some old manuscript, 



ACTIVE TRANSFORMATION OF PAST. 267 

obliterating some parts, altering the appearance of 
others, and even dislocating certain portions. Besides 
this passive process of transformation, there is a more 
active one in which our present minds co-operate. In 
memory, as in perception and introspection, there is a 
process of preparation or preadjustment of mind, and 
here will be found room for what I had called active 
error. This may be illustrated by the operation of " in- 
terpreting " an old manuscript which has got partially 
obliterated, or of " restoring " a faded picture ; in each 
of which operations error will be pretty sure to creep 
in through an importation of the restorer's own ideas 
into the relic of the past. 

Just as when distant objects are seen mistily our 
imaginations come into play, leading us to fancy that 
we see something completely and distinctly, so when 
the images of memory become dim, our present imagi- 
nation helps to restore them, putting a new patch 
into the old garment. If only there is some relic of the 
past event preserved, a bare suggestion of the way in 
which it may have happened will often suffice to pro- 
duce the conviction that it actually did happen in this 
way. The suggestions that naturally arise in our 
minds at such times will bear the stamp of our present 
modes of experience and habits of thought. Hence, in 
trying to reconstruct the remote past, we are constantly 
in danger of importing our present selves into our past 
selves. 

The kind of illusion of memory which thus depends 
on the spontaneous or independent activity of present 
imagination is strikingly illustrated in the curious 
cases of mistaken idectity with which the proceedings 



268 ILLUSIONS OF MEMORY. 

of our law courts supply us from time to time. When 
a witness in good faith, but erroneously, affirms that a 
man is the same as an old acquaintance of his, we may 
feel sure that there is some striking point or points of 
similarity between the two persons. But this of itself 
would only partly account for the illusion, since we 
often see new faces that, by a number of curious points 
of affinity, call up in a tantalizing way old and familiar 
ones. What helps in this case to produce the illu- 
sion is the preconception that the present man is the 
witness's old friend. That is to say, his recollection 
is partly true, though largely false. He does really 
recall the similar feature, movement, or tone of voice ; 
he only seems to himself to recall the rest of his friend's 
appearance ; for, to speak correctly, he projects the 
present impression into the past, and constructs his 
friend's face out of elements supplied by the new one. 
Owing to this cause, an illusion of memory is apt to 
multiply itself, one man's assertion of what happened 
producing by contagion a counterfeit of memory's record 
in other minds. 

I said just now that we tend to project our present 
modes of experience into the past. We paint our past 
in the hues of the present. Thus we imagine that 
things which impressed us in some remote period of 
life must answer to what is impressive in our present 
stage of mental development. For example, a person 
recalls a hill near the home of his childhood, and has 
the conviction that it was of great height. On revisit- 
ing the place he finds that the eminence is quite 
insignificant. How can we account for this ? For one 
thing, it is to be observed that to his undeveloped 



PAST INTEEPKETED BY PRESENT 269 

childish muscles the climbing to the top meant a con- 
siderable expenditure of energy, to be followed by a 
sense of fatigue. The man remembers these feelings, 
and " unconsciously reasoning " by present experience, 
that is to say, by the amount of walking which would 
now produce this sense of fatigue, imagines that the 
height was vastly greater than it really was. Another 
reason is, of course, that a wider knowledge of mountains 
has resulted in a great alteration of the man's standard 
of height. 

From this cause arises a tendency generally to 
exaggerate the impressions of early life. Youth is 
the period of novel effects, when all the world is fresh, 
and new and striking impressions crowd in thickly on 
the mind. Consequently, it takes much less to pro- 
duce a given amount of mental excitation in childhood 
than in after-life. In looking back on this part of our 
history, we recall for the most part just those events 
and scenes which deeply stirred our minds by their 
strangeness, novelty, etc., and so impressed themselves 
on the tablet of our memory ; and it is this sense of 
something out of the ordinary beat that gives the 
characteristic colour to our recollection. In other 
words, we remember something as wonderful, admir- 
able, exceptionally delightful, and so on, rather than as 
a definitely imagined event. This being so, we uncon- 
sciously transform the past occurrence by reasoning 
from our present standard of what is impressive. Who 
has not felt an unpleasant disenchantment on revisiting 
some church, bouse, or park that seemed a wondrous 
paradise to his young eyes? All our feelings are 
capable of leading us into this kind of illusion. What 



270 ILLUSIONS OF MEMORY. 

seemed beautiful or awful to us as children, is now 
pictured in imagination as corresponding to what 
moves our mature minds to delight or awe. One 
cannot help wondering what we should think of our 
early heroes or heroines if we could see them again 
with our adult eyes exactly as they were. 

While the past may thus take on an illusory hue 
through the very progress of our experience and our 
emotional life, it may become further transformed by 
a more conscious process, namely, the idealizing touch 
of a present feeling. The way in which the emotions 
of love, reverence, and so on, thus transform their lost 
objects is too well known to need illustration. Speak- 
ing generally, we may say that in healthy minds the 
play of these impulses of feeling results in a softening 
of the harsher features of the past, and in an idealization 
of its happier and brighter aspects. As Wordsworth 
says, we may assign to Memory a pencil — 

u That, softening objects, sometimes even 
Outstrips the heart's demand ; 

u That smoothes foregone distress, the lines 
Of lingering care subdues, 
Long-vanished happiness refines, 
And clothes in brighter hues." 1 

Enough has now been said, perhaps, to show in 
how many ways our retrospective imagination trans- 
forms the actual events of our past life. So thoroughly, 
indeed, do the relics of this past get shaken together 
in new kaleidoscopic combinations, so much of the 

1 This is, perhaps, what is meant by saying that people recall their 
past enjoyments more readily than their sufferings. Yet much seems 
to turn on temperament and emotional peculiarities. (For a fuller 
d scussion of the point, see my Pessimism, p. 344.) 



EXTENT OF TRANSFORMATION. 211 

result of later experiences gets imported into our early 
years, that it may well be asked whether, if the record 
of our actual life were ever read out to us, we should be 
able to recognize it. It looks as though we could be 
sure of recalling only recent events with any degree of 
accuracy and completeness. As soon as they recede at 
any considerable distance from us, they are subject to 
a sort of atmospheric effect. Much grows indistinct 
and drops altogether out of sight, and what is still 
seen often takes a new and grotesquely unlike shape. 
More than this, the play of fancy, like the action of 
some refracting medium, bends and distorts the out- 
lines of memory's objects, making them wholly unlike 
the originals. 

Hallucinations of Memory. 
We will now go on to the third class of mnemonic 
error, which I have called the spectra of memory, 
where there is not simply a transformation of the 
past event, but a complete imaginative creation of 
it. This class of error corresponds, as I have observed, 
to an hallucination in the region of sense-perception. 
And just as we distinguished between those halluci- 
nations of sense which arise first of all through some 
peripherally caused subjective sensation, and those 
which want even this element of reality and depend 
altogether on the activity of imagination, so we may 
mark off two classes of mnemonic hallucination. The 
false recollection may correspond to something past — 
and to this extent be a recollection — though not to 
any objective fact, but only to a subjective represen- 
tation of such a fact, as, for example, a dream. In 



272 ILLUSIONS OF MEMORY. 

this case the imitation of the mnemonic process nvtf 
be very definite and complete. Or the false recollec- 
tion may be wholly a retrojection of a present mental 
image, and so by no stretch of language be deserving 
of the name recollection. 

It is doubtful whether by any effort of will a person 
could bring himself to regard a figment of his present 
imagination as representative of a past reality. Defi- 
nite and complete hallucinations of this sort do not in 
normal circumstances arise. It seems necessary for a 
complete illusion of memory that there should be some- 
thing past and recovered at the moment, though this 
may not be a real personal experience. 1 On the 
other hand, it is possible, as we shall presently see, 
under certain circumstances, to create out of present 
materials, and in a vague and indefinite shape, pure 
phantoms of past experience, that is to say, quasi- 
mnemonic images to which there correspond no past 
occurrences whatever. 

All recollection, as we have seen, takes place by 
means of a present mental image which returns with 
a certain degree of vividness,, and' is instantaneously 
identified with some past event. In many cases this 
instinctive process cf identification proves to be 
legitimate, for, as a matter of fact, real impressions 

1 The only exception to this that I can think of is to be found 
in the power which I, at least, possess, after looking at a new object, 
of representing it as a familiar one. Yet this may be explained by 
saying that in the case of every object which is clearly apprehended 
there must be vague revivals of similar objects perceived before. 
Cases in which recent experiences tend, owing to their peculiar nature* 
very rapidly to assume the appearance of old events, will be con 
sidered presently. 



HALLUCINATIONS OF MEMOEY. 273 

are the first and the commonest source of such lively- 
mnemonic images. But it is not always so. There 
are other sources of our mental imagery which com- 
pete, so to speak, with the region of real personal 
experience. And sometimes these leave behind them 
a vivid image having all the appearance of a genuine 
mnemonic image. When this is so, it is impossible by 
a mere introspective glance to detect the falsity of the 
message from the past. We are in the same position 
as the purchaser in a jet market, where a spurious 
commodity has got inextricably mixed up with the 
genuine, and there is no ready criterion by which he 
can distinguish the true from the false. Such a 
person, if he purchases freely, is pretty sure to make 
a number of mistakes. Similarly, all of us are liable 
to take counterfeit mnemonic images for genuine ones ; 
that is to say, to fall into an illusion of " recollecting " 
what never really took place. 

But what, it may be asked, are these false and 
illegitimate sources of mnemonic images, these un- 
authorized mints which issue a spurious mental 
coinage, and so confuse the genuine currency ? They 
consist of two regions of our internal mental life, 
which most closely resemble the actual perception of 
real things in vividness and force, namely, dream- 
consciousness and waking imagination. Each of these 
may introduce into the mind vivid images which 
afterwards tend, under certain circumstances, to assume 
the guise of recollections of actual events. 

That our dream-experience may now and again 
lead us into illusory recollection has already been 
hinted. And it is easy to understand why this is so. 
13 



274 ILLUSIONS OF MEMORY. 

"When dreaming we have, as we have seen, a mental 
experience which closely approximates in intensity 
and reality to that of waking perception. Conse- 
quently, dreams may leave behind them, for a time, 
vivid images which simulate the appearance of real 
images of memory. Most of us, perhaps, have felt 
this after-effect of dreaming on our waking thoughts. 
It is sometimes very hard to shake off the impression 
left by a vivid dream, as, for example, that a dead 
friend has returned to life. During the day that 
follows the dream, we have at intermittent moments 
something like an assurance that we have seen our 
lost friend ; and though Ave immediately correct 
the impression by reflecting that we are recalling but 
a dream, it tends to revive within us with a strange 
pertinacity. 

In addition to this proximate effect of a dream 
in disturbing the normal process of recollection, there 
is reason to suppose that dreams may exert a more 
remote effect on our memories. So widely different in 
its form is our dreaming from our waking experience, 
that our dreams are rarely recalled as wholes with 
perfect distinctness. They revive in us only as dis- 
jointed fragments, and only for brief moments when 
some accidental resemblance in the present happens 
to stir the latent trace they have left on our minds. 
We get sudden flashes out of our dream-world, and the 
process is too rapid, too incomplete for us to identify 
the region whence the flashes come. 

It is highly probable that our dreams are, to a 
large extent, answerable for the sense of familiarity 
that we sometimes experience in visiting a new locality 



DEEAMS AND FALSE EECOLLECTION. 275 

or in seeing a new face. If, as we have found some of 
the best authorities saying, we are, when asleep, always 
dreaming more or less distinctly, and if, as we know, 
dreaming is a continual process of transformation of 
our waking impressions in new combinations, it is not 
surprising that our dreams should sometimes take the 
form of forecasts of our waking life, and that conse- 
quently objects and scenes of this life never before 
seen should now and ao-ain wear a familiar look. 

o 

That some instances of this puzzling sense of famili- 
arity can be explained in this way is proved. Thus, 
Paul Eadestock, in the work Schlaf unci Traum, already 
quoted, tells us : " When I have been taking a walk, 
with my thoughts quite unfettered, the idea has often 
occurred to me that I had seen, heard, or thought of 
this or that thing once before, without being able to 
recall when, where, and in what circumstances. This 
happened at the time when, with a view to the pub- 
lication of the present work, I was in the habit of 
keeping an exact record of my dreams. Consequently, 
I was able to turn to this after these impressions, and 
on doing so I generally found the conjecture confirmed 
that I had previously dreamt something like it." 
Scientific inquiry is often said to destroy all beautiful 
thoughts about nature and life ; but while it destroys 
it creates. Is it not almost a romantic idea that just 
as our waking life images itself in our dreams, so 
our dream-life may send back some of its shadowy 
phantoms into our prosaic every-day world, touching 
this with something of its own weird beauty ? 

Not only may dreams beget these momentary 
illusions of memory, they may give rise to something 



276 ILLUSIONS OF MEMORY. 

like permanent illusions. If a dream serves to connect 
a certain idea with a place or person, and subsequent 
experience does not tend to correct this, we may keep 
the belief that we have actually witnessed the event. 
And we may naturally expect that this result will 
occur most frequently in the case of those who 
habitually dream vividly, as young children. 

It seems to me that many of the quaint fancies 
which children get into their heads about things they 
hear of arise in this way. I know a person who, when 
a child, got the notion that when his baby-brother was 
weaned, he was taken up on a grassy hill and tossed 
about. He had a vivid idea of having seen this curious 
ceremony. He has in vain tried to get an explanation 
of this picturesque rendering of an incident of baby- 
hood from his friends, and has come to the conclusion 
that it was the result of a dream. If, as seems 
probable, children's dreams thus give rise to subse- 
quent illusions of memory, the fact would throw a 
curious light on some of the startling quasi-records 
of childish experience to be met with in autobio- 
graphical literature. 

Odd though it may at first appear, old age is said to 
resemble youth in this confusion of dream-recollection 
with the memory of waking experience. Dr. Car- 
penter 1 tells us of "a lady of advanced age who 
. . . continually dreams about passing events, and 
seems entirely unable to distinguish between her 
dreaming and her waking experiences, narrating the 
former with implicit belief in them, and giving direc- 
tions based on them." This confusion in the case 

1 Mental Physiology, p. 456. 



EFFECTS OF PAST D1AGINATION. 277 

of the old may possibly arise not from an increase in 
the intensity of the dreams, but from a decrease in the 
intensity of the waking impressions. As Sir Henry 
Holland remarks, 1 in old age life approaches to the 
state of a dream. 

The other source of what may, by analogy with 
the hallucinations of sense, be called the peri- 
pherally originating spectra of memory is waking 
imagination. In certain morbid conditions of mind, 
and in the case of the few healthy minds endowed 
with special imaginative force, the products of this 
mental activity, may, as we saw when dealing with 
illusions of perception, closely resemble dreams in 
their vividness and apparent actuality. When this is 
the case, illusions of memory may arise at once just 
as in the case of dreams. This will happen more 
easily when the imagination has for some time been 
occupied with the same group of ideal scenes, persons, 
or events. To Dickens, as is well known, his fictitious 
characters were for the time realities, and after he had 
finished his story their forms and their doings lingered 
with him, assuming the aspect of personal recollec- 
tions. So, too, the energetic activity of imagination 
which accompanies a deep and absorbing sympathy 
with another's painful experiences, may easily result 
in so vivid a realization of all their details as to leave 
an after-sense of personal suffering. All highly sym- 
pathetic persons who have closely accompanied beloved 
friends through a great sorrow have known something 
of this subsequent feeling. 

The close connection and continuity between nor- 
1 Mental Physiology, second edit., p. 172. 



278 ILLUSION OF MEMORY. 

mal and abnormal states of mind i3 illustrated in 
the fact that in insanity the illusion of taking past 
imaginations for past realities becomes far more power- 
ful and persistent. Abercrombie {Intellectual Powers, 
Tart III. sec. iv. § 2, " Insanity ") speaks of " visions 
of the imagination which have formerly been indulged 
in of that kind which we call waking dreams or 
castle-building recurring to the mind in this condition, 
and now believed to have a real existence." Thus, 
for example, one patient believed in the reality of the 
good luck previously predicted by a fortune-teller, 
Other writers on mental disease observe that it is a 
common thing for the monomaniac to cherish the 
delusion that he has actually gained the object of 
some previous ambition, or is undergoing some pre- 
viously dreaded calamity. 

Nor is it necessary to these illusions of memory 
that there should be any exceptional force of imagina- 
tion. A fairly vivid representation to ourselves of 
anything, whether real or fictitious, communicated by 
others, will often result in something very like a 
personal recollection. In the case of works of history 
and fiction, which adopt the narrative tense, this 
tendency to a subsequent illusion of memory is 
strengthened by the disposition of the mind at the 
moment of reading to project itself backwards as in 
an act of recollection. This is a point which will be 
farther dealt with in the next chapter. 

In most cases, however, illusions of memory growing 
out of previous activities of the imagination appear only 
after the lapse of some time, when in the natural course 
of things the mental images derived from actual ex- 



RECOLLECTIONS OF CHILDHOOD. 279 

perience would sink to a certain degree of faintness. 
Habitual novel-readers often catch, themselves mis- 
taking the echo of some passage in a good story for 
the trace left by an actual event. A person's name, 
a striking saying, and even an event itself, when we 
first come across it or experience it, may for a moment 
seem familiar to us, and to recall some past like 
impression, if it only happens to resemble something 
in the works of a favourite novelist. And so, too, any 
recital of another's experience, whether oral or literary, 
if it deeply interests us and awakens a specially vivid 
imagination of the events described, may easily be- 
come the starting-point of an illusory recollection. 

Children are in the habit of " drinking in " with 
their vigorous and eager imaginations what is told 
them and read to them, and hence they are specially 
likely to fall into this kind of error. Not only so : 
when they grow up and their early recollections lose 
their definiteness, becoming a few fragments saved 
from a lost past, it must pretty certainly happen that 
if any ideas derived from these recitals are preserved, 
they will simulate the form of memories. Thus, I 
have often caught myself for a moment under the 
sway of the illusion that I actually visited the Exhi- 
bition of 1851, the reason being that I am able to 
recall the descriptions given to me of it by my friends, 
and the excitement attending their journey to London 
on the occasion. It is to be added that repetition of 
the act of imagination will tend still further to deepen 
the subsequent feeling that we are recollecting some- 
thing. As Hartley well observes, a man, by repeating 
a story, easily comes to suppose that he remembers it. 1 

1 Loc. cit., p. 390. 



280 ILLUSIONS OF MEMORY. 

Here, then, we have another source of error that 
we must take into account in judging of the authen- 
ticity of an autobiographical narration of the events 
of childhood. The more imaginative the writer, the 
greater the risk of illusion from this source as well 
as from that of dream-fancies. It is highly probable, 
indeed, that in such full and explicit records of very 
early life as those given by Rousseau, by Goethe, or 
by De Quincey, some part of the quasi-narrative is 
based on mental images which come floating down 
the stream of time, not from the substantial world of 
the writer's personal experience, but from the airy 
region of dream-land or of waking fancy. 

It is to be added that even when the quasi- 
recollection does answer to a real event of childish 
history, it may still be an illusion. The fact that 
others, in narrating events to us, are able to awaken 
imaginations that afterwards appear as past realities, 
suggests that much of our supposed early recollection 
owes its existence to what our parents and friends have 
from time to time told us respecting the first stages of 
our history. 1 We see, then, how much uncertainty 
attaches to all autobiographical description of very 
early life. 

Modern science suggests another possible source of 
these distinct spectra of memory. May it not happen 
that, by the law of hereditary transmission, which is 
now being applied to mental as well as bodily phe- 
nomena, ancestral experiences will now and then reflect 

1 This source of error has not escaped the notice of autobiographera 
themselves. See the remarks of Goethe in the opening passages of 
his Wahrheit und Bichtung. 



RECOLLECTION OF PRENATAL EVENTS. 281 

themselves in our mental life, and so give rise to ap- 
parently personal recollections ? No one can say that 
this is not so. When the infant first steadies his eyes 
on a human face, it may, for aught we know, experience 
a feeling akin to that described above, when through 
a survival of dream-fancy we take some new scene to 
be already familiar. At the age when new emotions 
rapidly develop themselves, when our hearts? &re full 
of wild romantic aspirations, do there not seem to 
blend with the eager passion of the time deep reso- 
nances of a vast and mysterious past, and may not 
this feeling be a sort of reminiscence of prenatal, 
that is, ancestral experience ? 

This idea is certainly a fascinating one, wortliy to 
be a new scientific support for the beautiful thought 
of Plato and of Wordsworth. But in our present state 
of knowledge, any reasoning on this supposition would 
probably appear too fanciful. Some day we may find 
out how much ancestral experience is capable of be- 
queathing in this way, whether simply shadowy, unde- 
finable mental tendencies, or something like definite 
concrete ideas. If, for example, it were found that a 
child that was descended from a line of seafaring 
ancestors, and that had never itself seen or heard of 
the " dark-gleaming sea," manifested a feeling of re- 
cognition when first beholding it, we might be pretty 
sure that such a thing as recollection of prenatal events 
does take place. But till we have such facts, it seems 
better to refer the " shadowy recollections " to sources 
which fall within the individual's own experience. 

We may now pass to those hallucinations of 
memory which are analogous to the centrally excited 



282 ILLUSIONS OF MEMOES. 

hallucinations of sense-perception. As I have ob- 
served, these are necessarily vague and imperfectly 
developed. 

I have already had occasion to touch on the fact of 
the vast amount of our forgotten experience. And I 
observed that forgetfulness was a common negative con- 
dition of mnemonic illusion. I have now to complete 
this statement by the observation that total forget- 
fulness of any period or stage of our past experience 
necessarily tends to a vague kind of hallucination. In 
looking back on the past, we see no absolute gaps 
in the continuity of our conscious life ; our image 
of this past is essentially one of an unbroken series 
of conscious experiences. But if through forget- 
fulness a part of the series is effaced from memory, 
how, it may be asked, is it possible to construct this 
perfectly continuous line ? The answer is that we fill 
up such lacunar vaguely by help of some very im- 
perfectly imagined common type of conscious expe- 
rience. Just as the eye sees no gap in its field of 
vision corresponding to the " blind spot " of the retina, 
but carries its impression over this area, so memory 
sees no lacuna in the past, but carries its image of 
conscious life over each of the forgotten spaces. 

Sometimes this process of filling in gaps in the 
past becomes more complete. Thus, for example, in 
recalling a particular night a week or so ago, I instinc- 
tively represent it to myself as so many hours of lying 
in bed with the waking sensations appropriate to the 
circumstances, as those of bodily warmth and rest, and 
of the surrounding silence and darkness. 

It is apparent that I cannot conceive myself apart 



FILLING UP GAPS IN MEMOKY. 283 

from some mode of conscious experience. In thinking 
of myself in any part of the past or future in which 
there is actually no consciousness, or of which the con- 
scious content is quite unknown to me, I necessarily 
imagine myself as consciously experiencing something. 
If I picture myself under any definitely conceived 
circumstances, I irresistibly import into my mental 
image the feelings appropriate to these surroundings. 
In this way, people tend to imagine themselves after 
death as lying in the grave, feeling its darkness and 
its chilliness. If the circumstances of the time are 
not distinctly represented, the conception of the con- 
scious experience which constitutes that piece of the 
ego is necessarily vague, and seems generally to resolve 
itself into a representation of ourselves as dimly selj- 
conseious. What this consciousness of self consists of 
is a point that will be taken up presently. 

Illusions with respect to Personal Identity. 
It would seem to follow from these errors in imagi- 
natively filling up our past life, that our conscious- 
ness of personal identity is by no means the simple 
and exact process which it is commonly supposed to 
be. I have already remarked that the very fact of 
there being so large a region of the irrevocable in our 
past experience proves our consciousness of personal 
continuity to be largely a matter of inference, or of 
imaginative conjecture, and not simply of immediate 
recollection. Indeed, it may be said that our power of 
ignoring whole regions of the past and of leaping 
complacently over huge gaps in our memory and 
linking on cons-ious experience with conscious ex- 



284 illusions or memory. 

perience, involves an illusory sense of continuity, and 
so far of personal identity. Thus, our ordinary image 
of our past life, if only by omitting the very large 
fraction passed in sleep, in at least an approximately 
unconscious state, clearly contains an ingredient of 
illusion. 1 

It is to be added that the numerous falsifications of 
our past history, which our retrospective imagination 
is capable of perpetrating, make our representation of 
ourselves at different moments and in different stages 
of our past history to a considerable extent illusory. 
Thus, though to mistake a past dream-experience for a 
waking one may not be to lose or confuse the sense of 
identity, since our dreams are, after all, a part of our 
experience, yet to imagine that we have ourselves 
seen what we have only heard from another or read is 
clearly to confuse the boundaries of our identity. And 
with respect to longer sections of our history, it is 
plain that when we wrongly assimilate our remote to 
our present self, and clothe our childish nature with 
the feelings and the ideas of our adult life, we identify 
ourselves overmuch. In this way, through the cor- 
ruption of our memory, a kind of sham self gets mixed 
up with the real self, so that we cannot, strictly speak- 
ing, be sure that when we project a mnemonic image 
into the remote past we are not really running away 
from our true personality. 

One wonders whether those persons who, in consequence of an 
injury to their brain, periodically pass from a normal into an abnormal 
condition of mind, in each of -which there is little or no memory of the 
contents of the other state, complete their idea of personal continuity 
in each state by the same kind of process as that described hi tho 
text. 



REMEMBERED AND IMAGINED SELVES. 285 

So far I have been touching only on slight errors 
in the recognition of that identical self which is repre- 
sented as persisting through all the fluctuations of 
conscious life. Other and grosser illusions connected 
with personal identity are also found to be closely 
related to defects or disturbances of the ordinary 
mnemonic process, and so can be best treated here. 
In order to understand these, we must inquire a little 
into the nature of our idea and consciousness of a per- 
sistent self. Here, again, I would remind the reader that 
I am treating the point only so far as it can be treated 
scientifically or empirically, that is to say, by examin- 
ing what concrete facts or data of experience are 
taken up into the idea of self. I do not wish to fore- 
close the philosophic question whether anything more 
than this empirical content is involved in the con- 
ception. 

My idea of myself as persisting appears to be 
built up of certain similarities in the succession of my 
experiences. Thus, my permanent self consists, on the 
bodily side, of a continually renewable perception of 
my own organism, which perception is mainly visual 
and tactual, and which remains pretty constant 
within certaiu limits of time. With this objective 
similarity is closely conjoined a subjective similarity. 
Thus, the same sensibilities continue to characterize 
the various parts of my organism. Similarly, there are 
the higher intellectual, emotional, and moral peculiari- 
ties and dispositions. My idea of my persistent self is 
essentially a collective image representing a relatively 
unchanging material object, endowed with unchanging 
sensibilities and forming a kind of support for per- 
manent higher mental attributes. 



286 ILLUSIONS OF MEMORY. 

The construction of this idea of an enduring un- 
changing ego is rendered very much easier by the fact 
that certain concrete feelings are approximately con- 
stant elements in our mental life. Among these must 
be ranked first that dimly discriminated mass of 
organic sensation which in average states of health 
is fairly constant, and which stands in sharp contrast 
to the fluctuating external sensations. These feelings 
enter into and profoundly colour each person's mental 
image of himself. In addition to this, there are the 
frequently recurring higher feelings, the dominant 
passions and ideas which approximate more or less 
closely to constant factors of our conscious experience. 

This total image of the ego becomes defined and 
rendered precise by a number of distinctions, as that 
between my own body or that particular material 
object with which are intimately united all my feelings, 
and other material objects in general; then between 
my organism and other human organisms, with which 
I learn to connect certain feelings answering to my 
own, but only faintly represented instead of actually 
realized feelings. To these prime distinctions are 
added others, hardly less fundamental, as those be- 
tween my individual bodily appearance and that of 
other living bodies, between my personal and charac- 
teristic modes of feeling and thinking and those of 
others, and so on. 

Our sense of personal identity may be said to be 
rooted in that special side of the mnemonic process 
which consists in the linking of all sequent events 
together by means of a thread of common conscious- 
ness. It is closely connected with that smooth, 



CONTENTS OF THE IDEA OF SELF. 287 

gliding movement of imagination which appears to 
involve some more or less distinct consciousness of 
the uniting thread of similarity. And so long as this 
movement is possible, so long, that is to say, as retro- 
spective imagination detects the common element, 
which we may specifically call the recurring con- 
sciousness of self, so long is there the undisturbed 
assurance of personal identity. Nay, more, even when 
such a recognition might seem to be difficult, if not 
impossible, as in linking together the very unlike 
selves, viewed both on their objective and subjective 
sides, of childhood, youth, and mature life, the mind 
manages, as we have seen, to feign to itself a suffi- 
cient amount of such similarity. 

But this process of linking stage to stage, of discern- 
ing the common or the recurring amid the changing 
and the evanescent, has its limits. Every great and 
sudden change in our experience tends, momentarily at 
least, to hinder the smooth reflux of imagination. It 
makes too sharp a break in our conscious life, so that 
imagination is incapable of spanning the gap and 
realizing the then and the now as parts of a connected 
continuous tissue. 1 

These changes may be either objective or subjec- 
tive. Any sudden alteration of our bodily appear- 
ance sensibly impedes the movement of imagination. 
A patient after a fever, when he first looks in the glass, 

1 The reader will remark that this condition of clear intellectual 
consciousness, namely, a certain degree of similarity and continuity of 
character in our successive mental states, is complementary to the 
other condition, constant change, already referred to. It may, per- 
haps, be said that all clear consciousness lies between two extremes of 
excessive sameness and excessive difference. 



288 ILLUSIONS OF MEMORY. 

exclaims, " I don't know myself." More commonly the 
bodily changes which affect the consciousness of an 
enduring self are such as involve considerable altera- 
tions of ccensesthesis, or the mass of stable organic 
sensation. Thus, the loss of a limb, by cutting off 
a portion of the old sensations through which the 
organism may be said to be immediately felt, and 
by introducing new and unfamiliar feelings, will dis- 
tinctly give a shock to our consciousness of self. 

Purely subjective changes, too, or, to speak cor- 
rectly, such as are known subjectively only, will suffice 
to disturb the sense of personal unity. Any great 
moral shock, involving something like a revolution in 
our recurring emotional experience, seems at the 
moment to rupture the bond of identity. And even 
some time after, as I have already remarked, such 
cataclysms in our mental geology lead to the imagina- 
tive thrusting of the old personality away from the 
new one under the form of a " dead self." l 

We see, then, that the failure of our ordinary 
assurance of personal identity is due to the recog- 
nition of difference without similarity. It arises from 
an act of memory — for the mind must still be able to 
recall the past, dimly at least — but from a memory 
which misses its habitual support in a recognized 

1 It follows that any great transformation of our environment may 
lead to a partial confusion with respect to self. For not only do great 
and violent changes in our surroundings beget profound changes in 
our feelings and ideas, but since the idea of self is under one of its 
aspects essentially that of a relation to not-self, any great revolution 
in the one term will confuse the recognition of the other. This fact is 
expressed in the common expression that we " lose ourselves " when in 
unfamiliar surroundings, and the process of orientation, or " taking 
our bearings," fails. 



APPAEENT EUPTUEES OF IDENTITY. 289 

element of constancy. If there is no memory, that is 
to say, if the past is a complete blank, the mind 
simply feels a rupture of identity without any trans- 
formatiou of self. This is our condition on awaking 
from a perfectly forgotten period of sleep, or from a 
perfectly unconscious state (if such is possible) when 
induced by anaesthetics. Such gaps are, as we have 
seen, easily filled up, and the sense of identity restored 
by a kind of retrospective " skipping." On the other 
hand, the confusion which arises from too great and 
violent a transformation of our remembered experiences 
is much less easily corrected. As long as the recollec- 
tion of the old feelings remains, and with this the 
sense of violent contrast between the old and the new 
ones, so long will the illusion of two sundered selves 
tend to recur. 

The full development of this process of imaginative 
fission or cleavage of self is to be met with in mental 
disease. The beginnings of such disease, accompanied 
as they commonly are with disturbances of bodily 
sensations and the recurring emotions, illustrate in a 
very interesting way the dependence of the recog- 
nition of self on a certain degree of uniformity in the 
contents of consciousness. The patient, when first 
aware of these changes, is perplexed, and often regards 
the new feelings as making up another self, a foreign 
Tu, as distinguished from the familiar Ego. And 
sometimes he expresses the relation between the old 
and the new self in fantastic ways, as when he imagines 
the former to be under the power of some foreign 
personality. 

When the change is complete, the patient is apt to 



2D0 ILLUSIONS OF MEMORY. 

think of his former self as detached from his present, 
and of his previous life as a kind of unreal dream ; and 
this fading away of the past into shadowy unreal forms 
has, as its result, a curious aberration in the sense of 
time. Thus, it is said that a patient, after being in an 
asylum only one day, will declare that ho has been 
there a year, five years, and even ten years. 1 This 
confusion as to self naturally becomes the starting- 
point of illusions of perception ; the transformation of 
self seeming to require as its logical correlative (for 
there is a crude logic even in mental disease) a trans- 
formation of the environment. When the disease is 
fully developed under the particular form of mono- 
mania, the recollection of the former normal self 
commonly disappears altogether, or fades away into 
a dim image of some perfectly separate personality. A 
new ego is now fully substituted for the old. In other 
and more violent forms of disease (dementia) the power 
of connecting the past and present may disappear 
altogether, and nothing but the disjecta membra of an 
ego remain. 

Enough has, perhaps, been said to show how much 
of uncertainty and of self-deception enters into the pro- 
cesses of memory. This much-esteemed faculty, valu- 
able and indispensable though it certainly is, can clearly 
lay no claim to that absolute infallibility which is some- 
times said to belong to it. Our individual recollection, 

1 On these disturbances of memory and self-recognition in insanity, 
see Griesingcr, op. cil., pp. 49-51 ; also Kibot, "Des De'sordros Ge'ne'raux 
do la Me'moiie," in the Itevue Fhilosophique, August, 1880. It ia 
related by Leuret (Fragments Psych, sur la Folie, p. 277) that a patient 
spoke of his former self as " la pcrsonne dc moi-nicme." 



VALUE OF MEMORY. 291 

left to itself, is liable to a number of illusions even with 
regard to fairly recent events, and in the case of remote 
ones it may be said to err habitually and uniformly in 
a greater or less degree. To speak plainly, we can 
never be certain on the ground of our personal recol- 
lection alone that a distant event happened exactly 
in the way and at the time that we suppose. Nor doe i 
there seem to be any simple way by mere reflection 
on the contents of our memory of distinguishing what 
kinds of recollection are likely to ba illusory. 

How, then, it may be asked, can we ever be certain 
that we are faithfully recalling the actual events of 
the past ? Given a fairly good, that is, a cultivated 
memory, it may be said that in the case of very recent 
events a man may feel certain that, when the con- 
ditions of careful attention at the time to what 
really happened were present, a distinct recollection 
is substantially correct. Also it is obvious that with 
respect to all repeated experiences our memories afford 
practically safe guides. When memory becomes the 
basis of some item of generalized knowledge, as, for 
example, of the truth that the pain of indigestion has 
followed a too copious indulgence in rich food, there is 
little room for an error of memory properly so called 
On the other hand, when an event is not repeated in 
our experience, but forms a unique link in our personal 
history, the chances of error increase with the distance 
of the event ; and here the best of us will do well to. 
have resort to a process of verification or, if neces- 
sary, of correction. 

In order thus to verify the utterances of memory, 
we must look beyond our own internal mental states 



292 ILLUSIONS OF MEMORY. 

to some external facts. Thus, the recollections of our 
early life may often be tested by letters written by 
ourselves or our friends at the time, by diaries, and so 
on. When there is no unerring objective record to 
be found, we may have recourse to the less satis- 
factory method of comparing our recollections with 
those of others. By so doing we may reach a rough 
average recollection which shall at least be free from 
any individual error corresponding to that of personal 
equation in perception. But even thus we cannot be 
sure of eliminating all error, since there may be a 
cause of illusion acting on all our minds alike, as, for 
example, the extraordinary nature of the occurrence, 
which would pretty certainly lead to a common ex- 
aggeration of its magnitude, etc., and since, moreover, 
this process of comparing recollections affords an oppor- 
tunity for that reading back a present preconception 
into the past to which reference has already been made. 
The result of our inquiry is less alarming than it 
looks at first sight. Knowledge is valuable for action, 
and error is chiefly hurtful in so far as it misdirects 
conduct. Now, in a general way, we do not need to 
act upon a recollection of single remote events ; our 
conduct is sufficiently shaped by an accurate recollec- 
tion of single recent events, together with those bundles 
of recollections of recurring events and sequences of 
events which constitute our knowledge of ourselves 
and our common knowledge of the world about us. 
Nature has done commendably well in endowing us 
with the means of cultivating our memories up to this 
point, and we ought not to blame her for not giving us 
powers which would only very rarely prove of any 
appreciable practical service to us. 



( 293 ) 

NOTE. 

MOMENTARY ILLUSIONS OF SELF-CONSCIOUSNESS. 

The account of the apparent ruptures in our 
personal identity given in this chapter may help us 
to understand the strange tendency to confuse self 
with other objects which occasionally appears in 
waking consciousness and in dreams. These errors 
may be said generally to be due to the breaking up 
of the composite image of self into its fragments, and 
the regarding of certain of these only. Thus, the 
momentary occurrence of partial illusion in intense 
sympathy with others, including that imaginative pro- 
jection of self into inanimate objects, to which refer- 
ence has already been made, may be said to* depend 
on exclusive attention to the subjective aspect of self, 
to the total disregard of the objective aspect. In 
other words, when we thus momentarily " lose our- 
selves," or merge our own existence in that of another 
object, we clearly let drop out of sight the visual re- 
presentation of our own individual organism. On the 
other hand, when in dreams we double our personality, 
or represent to ourselves an external self which be- 
comes the object of visual perception, it is probably 
because we isolate in imagination the objective aspect 
of our personality from the other and subjective aspect. 
It is not at all unlikely that the several confusions of 
self touched on in this chapter have had something 
to do with the genesis of the various historical theories 
of a transformed existence, as, for example, the cele- 
brated doctrine of metempsychosis. 



CHAPTER XL 

ILLUSIONS OF BELIEF. 

Oue knowledge is commonly said to consist of two large 
varieties — Presentative and Representative. Represen- 
tative knowledge, again, falls into two chief divisions. 
The first of these is Memory, which, though not primary 
or original, like presentative knowledge, is still re- 
garded as directly or intuitively certain. The second 
division consists of all other representative knowledge 
besides memory, including, among other varieties, our 
anticipations of the future, our knowledge of others' 
past experience, and our general knowledge about 
things. There is no one term which exactly hits off 
this large sphere of cognition: I propose to call it 
Belief. I am aware that this is by no means a perfect 
word for my purpose, since, on the one hand, it sug- 
gests that every form of this knowledge must be less 
certain than presentative or mnemonic knowledge, 
which cannot be assumed ; and since, on the other 
hand, the word is so useful a one in psychology, for 
the purpose of marking off the subjective fact of 
assurance in all kinds of cognition. Nevertheless, 
I know not what better one I could select in order to 



IMMEDIATE BELIEF. 295 

make my classification answer as closely as a scientific 
treatment will allow to the deeply fixed distinctions 
of popular psychology. 

It might at first seem as if perception, introspecs 
tion, and memory must exhaust all that is meant by 
immediate, or self-evident, knowledge, and as if what I 
have here called belief must be uniformly mediate, 
derivate, or inferred knowledge. The apprehension 
of something now present to the mind, externally or 
internally, and the reapprehension through the pro- 
cess of memory of what was once so apprehended, 
might appear to be the whole of what can by any 
stretch of language be called direct cognition of 
things. This at least would seem to follow from the 
empirical theory of knowledge, which regards per- 
ception and memory as the ground or logical source 
of all other forms of knowledge. 

And even if we suppose, with some philosophers, that 
there are certain innate principles of knowledge, it 
seems now to be generally allowed that these, apart 
from the particular facts of experience, are merely ab- 
stractions ; and that they only develop into complete 
knowledge when they receive some empirical content, 
which must be supplied either by present perception 
or by memory. So that in this case, too, all definite 
concrete knowledge would seem to be either presenta- 
tive cognition, memory, or, lastly, some mode of in- 
ference from these. 

A little inquiry into the mental operations which 
I here include under the name belief will show, how- 
ever, that they are by no means uniformly processe- 
of inference. To take the simplest form of such know- 



296 ILLUSIONS OF BELIEF. 

ledge, anticipation of some personal experience : this 
may arise quite apart from recollection, as a spontaneous 
projection of a mental image into the future. A per- 
son may feel "intuitively certain" that something is 
going to happen to him which does not resemble any- 
thing in his past experience. Not only so ; even when 
the expectation corresponds to a bit of past expe- 
rience, this source of the expectation may, under cer- 
tain circumstances, be altogether lost to view, and the 
belief assume a secondarily automatic or intuitive 
character. Thus, a man may have first entertained a 
belief in the success of some undertaking as the result 
of a rough process of inference, but afterwards go on 
trusting when the grounds for his confidence are wholly 
lost sight of. 

This much may suffice for the present to show that 
belief sometimes approximates to immediate, or self- 
evident, conviction. How far this is the case will 
come out in the course of our inquiry into its different 
forms. This being so, it will be needful to include 
in our present study the errors connected with the 
process of belief in so far as they simulate the imme- 
diate instantaneous form of illusion. 

What I have here called belief may be roughly 
distinguished into simple and compound belief. By a 
simple belief I mean one which has to do with a single 
event or fact. It includes simple modes of expectation, 
as well as beliefs in single past facts not guaranteed by 
memory. A compound belief, on the other hand, has 
reference to a number of events or facts. Thus, our 
belief in the continued existence of a particular object, 
as well as our convictions respecting groups or classes 



BELIEF AS SIMPLE AND COMPOUND. 297 

of events, must be regarded as compound, since they 
can be shown to include a number of simple beliefs. 

A. Simple Illusory Belief: Expectation. 

It will be well to begin our inquiry by examin- 
ing the errors connected with simple expectations, 
so far as these come under our definition of illusion. 
And here, following our usual practice, we may set 
out with a very brief account of the nature of • the 
intellectual process in its correct form. For this pur- 
pose we shall do well to take a complete or definite 
anticipation of an event as our type. 1 

The ability of the mind to move forward, forecasting 
an order of events in time, is clearly very similar to its 
power of recalling events. Each depends on the 
capability of imagination to represent a Sequence of 
events or experiences. The difference between the 
two processes is that in anticipation the imagination 
setting out from the present traces the succession of 
experiences in their actual order, and not in the 
reverse order. It would thus appear to be a more 
natural and easy process than recollection, and obser- 
vation bears out this conclusion. Any object present 
to perception which is associated with antecedents and 
consequents with the same degree of cohesion, calls up 
its consequents rather than its antecedents. The 
spectacle of the rising of the sun carries the mind 
much more forcibly forwards to the advancing morn- 

1 In the following account of the process of belief and its errors, I 
am going over some of the ground traversed by my essay on Belief, 
its Varieties and Conditions ("Sensation and Intuition," ch. iv.). To 
this essay I must refer the reader for a fuller analysis of the subject 
14 



298 ILLUSIONS OF BELIEF. 

ing than backwards to the receding night. And there 
is good reason to suppose that in the order of mental 
development the power of distinctly expecting an 
event precedes that of distinctly recollecting one. 
Thus, in the case of the infant mind, as of the animal 
intelligence, the presence of signs of coming events, 
as the preparation of food, seems to excite distinct and 
vivid expectation. 1 

As a mode of assurance, expectation is clearly 
marked off from memory, and is not explainable by 
means of this. It is a fundamentally distinct kind of 
conviction. So far as we are capable of analyzing it, 
we may say that its peculiarity is its essentially active 
character. To expect a thing is to have stirred the 
active impulses, including the powers of attention ; it 
is to be on the alert for it, to have the attention 
already focussed for it, and to begin to rehearse the 
actions which the actual happening of the event — for 
example, the approach of a welcome object — would 
excite. It thus stands in marked contrast to memory, 
which is a passive attitude of mind, becoming active 
only when it gives rise to the' expectation of a recur- 
rence of the event. 2 

And now let us pass to the question whether ex- 
pectation ever takes the form of immediate knowledge. 

1 For an account of the difference of mechanism in memory and 
expectation, see Taiiie, De V Intelligence, 2ieme partio, livre premier, 
ch. ii. sec. 6. 

2 J. S. Mill distinguishes expectation as a radically distinct mode 
of belief from memory, but does not bring out the contrast with 
respect to activity here emphasized (James Mill's Analysis of the 
Human Mind, edited by J. S. Mill, p. 411, etc.). For a fuller state- 
mcnt of my view of the relation of belief to action, as compared with 
that of Professor Bain, see my earlier work. 



EXPECTATION AND RECOLLECTION. 299 

It may, perhaps, be objected that the anticipation of 
something future cannot be knowledge at all in the 
sense in which the perception of something present or 
the recollection of something past is knowledge. But 
this objection, when examined closely, appears to be 
frivolous. Because the future fact has not yet come 
into the sphere of actual existence, it is none the less 
the object of a perfect assurance. 1 

But, even if it is conceded that expectation is 
knowledge, the objection may still be urged that it 
cannot be immediate, since it is the very nature of 
expectation to ground itself on memory. I have 
already hinted that this is not the case, and I shall 
now try to show that what is called expectation 
covers much that is indistinguishable from immediate 
intuitive certainty, and consequently offers room for 
an illusory form of error. 

Let us set out with the simplest kind of expecta- 
tion, the anticipation of something about to happen 
within the region of our personal experience, and 
similar to what has happened before. And let the 
coming of the event be first of all suggested by some 
present external fact or sign. Suppose, for example, 
that the sky is heavy, the air sultry, and that I have a 
bad headache ; I confidently anticipate a thunderstorm. 
It would commonly be said that such an expectation is 
a kind of inference from the past. I remember that 
these appearances have been followed by a thunderstorm 
very often, and I infer that they will in this new case 
be so followed. 

1 For some good remarks on the logical aspects of future events as 
matters of fact, see Mr. Venn's Logic of Chance, ch. x. 



300 ILLUSIONS OF BELIEF. 

To this, however, it may be replied that in most cases 
there is no conscious going back to the past at all. As 
I have already remarked, anticipation is pretty certainly 
in advance of memory in early life. And even after 
the habit of passing from the past to the future, from 
memory to expectation, has been formed, the number 
of the past repetitions of experience would prevent the 
mind's clearly reverting to them. And, further, the 
very force of habit would tend to make the transition 
from memory to expectation more and more rapid, 
automatic, and unconscious. Thus it comes about that 
all distinctly suggested approaching events seem to be 
expected by a kind of immediate act of belief. The 
present signs call up the representation of the coming 
event with all the force of a direct intuition. At 
least, it may be said that if a process of inference, it is 
one which has the minimum degree of consciousness. 

It might still be urged that the mind passes from 
the present facts as signs, and so still performs a kind 
of reasoning process. This is, no doubt, true, and 
differentiates expectation from perception, in which 
there is no conscious transition from the presented to 
the represented. Still I take it that this is only a 
process of reasoning in so far as the sign is consciously 
generalized, and this is certainly not true of early 
expectations, or even of any expectations in a wholly 
uncultivated mind. 

For these reasons I think that any errors involved 
in such an anticipation may, without much forcing, be 
brought under our definition of illusion. When due 
altogether to the immediate force of suggestion in a 
present object or event, and not involving any con- 



INTUITIVE EXPECTATION. 301 

scions transition from past to future, or from general 
truth to particular instance, these errors appear to me 
to have more of the character of illusions than of that 
of fallacies. 

Much the same thing may be said about the 
vivid anticipations of a familiar kind of experience 
called up by a clear and consecutive verbal suggestion. 
When a man, even with an apparent air of playfulness, 
tells me that something is going to happen, and gives a 
consistent consecutive account of this, I have an antici- 
pation which is not consciously grounded on any past 
experience of the value of human testimony in general, 
or of this person's testimony in particular, but which is 
instantaneous and quasi-immediate. Consequently, any 
error connected with the mental act approximates to an 
illusion. 

So far I have supposed that the anticipated event 
is a recurring one, that is to say, a kind of experience 
which has already become familiar to us. This, how- 
ever, holds good only of a very few of our experiences. 
Our life changes as it progresses, both outwardly and 
inwardly. Many of our anticipations, when first formed, 
involve much more than a reproduction of a past 
experience, namely, a complex act of constructive 
imagination. Our representations of these untried ex- 
periences, as, for example, those connected with a new 
set of circumstances, a new social condition, a new mode 
of occupation, and so on, are clearly at the first far from 
simple processes of inference from the past. They are 
put together by the aid of many fragmentary images, 
restored by distinct threads of association, yet by a 
process so rapid as to appear like an intuition. Indeed, 



302 ILLUSIONS OF BELIEF. 

the anticipation of such, new experiences more often 
resembles an instantaneous imaginative intuition than 
a process of conscious transition from old experiences. 
In the case of these expectations, then, there would 
clearly seem to be room for illusion from the first. 

But even supposing that the errors connected 
with the first formation of an expectation cannot 
strictly be called illusory, we may see that such simple 
expectation will, in certain cases, tend to grow into 
something quite indistinguishable from illusion. I 
refer to expectations of remote events which allow of 
frequent renewal. Even supposing the expectation to 
have originated from some rational source, as from a 
conscious inference from past experience, or from the 
acceptance of somebody's statement, the very habit of 
cherishing the anticipation tends to invest it with an 
automatic self-sufficient character. To all intents and 
purposes the prevision becomes intuitive, by which 
I mean that the mind is at the time immediately cer- 
tain that something is going to happen, without need- 
ing to fall back on memory or reflection. This being 
so, whenever the initial process of inference or quasi- 
inference happens to have been bad, an illusory expecta- 
tion may arise. In other words, the force of repetition 
and habit tends to harden what may, in its initial 
form, have resembled a kind of fallacy into an illusion. 

And now let us proceed further. When a permanent 
expectation is thus formed, there arises the possibility 
of processes which favour illusion precisely analogous 
to those which we have studied in the case of memory. 

In the first place, the habit of imagining a future 
event is attended with a considerable amount of 



PERMANENT EXPECTATIONS. 303 

illusion as to time or remoteness. After what has 
been said respecting the conditions of such error in 
the case of memory, a very few words will suffice 
here. 

It is clear, then, in the first place, that the mind 
will tend to shorten any period of future time, and so 
to antedate, so to speak, a given event, in so far as the 
imagination is able clearly and easily to run over its 
probable experiences. From this it follows that re- 
peated iorecastings of series of events, by facilitating 
the imaginative process, tend to beget an illusory 
appearance of contraction in the time anticipated 
Moreover, since in anticipation so much of each 
division of the future time-line is unknown, it is 
obviously easy for the expectant imagination to skip 
over long intervals, and so to bring together widely 
remote events. 

In addition to this general error, there are more 
special errors. As in the case of recollection, vividness 
of mental image suggests propinquity; and accord- 
ingly, all vivid anticipations, to whatever cause the 
vividness may be owing, whether to powerful sugges- 
tion on the part of external objects, to verbal suggestion. 
or to spontaneous imagination and feeling, are apt to 
represent their objects as too near. 

It follows that an event intensely longed for, in so, 
far as the imagination is busy in representing it, will 
seem to approach the present. At the same time, as 
we have seen, an event much longed for commonly 
appears to be a great while coming, the explanation 
being that there is a continually renewed contradiction 
between anticipation and perception. The self-adjust- 



304 ILLUSIONS OF BELIEF. 

merit of tlie mind in the attitude of expectant attention 
proves again and again to be vain and futile, and it is 
this fact which brings home to it the slowness of the 
sequences of perceived fact, as compared with the 
rapidity of the sequences of imagination. 

When speaking of the retrospective estimate of 
time, I observed that the apparent distance of an event 
depends on our representation of the intervening 
time-segment. And the same remark applies to the 
prospective estimate. Thus, an occurrence which we 
expect to happen next week will seem specially near if 
we know little or nothing of the contents of the inter- 
vening sp.sce, for in this case the imagination does 
not project the experience behind a number of other 
distinctly represented events. 

Finally, it is to be remarked that the prospective 
appreciation of any duration will tend to err relatively 
by way of excess, where the time is exceptionally filled 
out with clearly expected and deeply interesting ex- 
periences. To the imagination of the child, a holiday, 
filled with new experiences, appears to be boundless. 

Thus far I have assumed that the date of the 
future event is a matter which might be known. It is, 
however, obvious, from the very nature of knowledge 
with respect to the future, that we may sometimes be 
certain of a thing happening to us without knowing 
with any degree of definiteness when it will happen. 
In the case of these temporally undefined expectations, 
the law already expounded holds good that all vividness 
of representation tends to lend the things represented 
an appearance of approaching events. On the other 
hand, there are some events, such as our own death, 



MISREPRESENTATION OF FUTURE. 305 

which our instinctive feelings tend to banish to a region 
so remote as hardly to be realized at all. 

So much with respect to errors in the localizing 
of future events. 

In the second place, a habit of imagining a future 
event or group of events will give play to those 
forces which tend to transform a mental image. In 
other words, the habitual indulgence of a certain 
anticipation tends to an illusory view, not only of the 
" when ? " but also of the " how ? " of the future event. 
These transformations, due to subtle processes of 
emotion and intellect, and reflecting the present habits 
of these, exactly resemble those by which a remem- 
bered event becomes gradually transformed. Thus, we 
carry on our present habits of thought and feeling into 
the remote future, foolishly imagining that at a distant 
period of life, or in greatly altered circumstances, we 
shall desire and aim at the same things as now in our 
existing circumstances. In close connection with this 
forward projection of our present selves, there betrays 
itself a tendency to look on future events as answer- 
ing to our present desires and aspirations. In this 
way, we are wont to soften, beautify, and idealize the 
future, marking it off from the hard matter-of-fact 
present. 

The less like the future experience to our past expe- 
rience, or the more remote the time anticipated, the 
greater the scope for such imaginative transformation. 
And from this stage of fanciful transformation of a 
future reality to the complete imaginative creation of 
such a reality, the step is but a small one. Here we 
reach the full development of illusory expectation, 



306 ILLUSIONS OF BELIEF. 

that whicli corresponds to hallucination in the region 
of sense-perception. 

In order to understand these extreme forms of 
illusory expectation, it will be necessary to say some- 
thing more about the relation of imagination to antici- 
pation in general. There are, I conceive, good reasons 
for saying that any kind of vivid imagination tends 
to pass into a semblance of an expectation of a coming 
personal experience, or an event that is about to happen 
within the sphere of our own observation. It has long 
been recognized by writers, among whom I may men- 
tion Dugald Stewart, that to distinctly imagine an 
event or object is to feel for the moment a degree of 
belief in the corresponding reality. Now, I have already 
said that expectation is probably a more natural and 
an earlier developed state of mind than memory. And 
so it seems probable that any mental image which 
happens to take hold on the mind, if not recognized 
as one of memory, or as corresponding to a fact in some- 
body else's experience, naturally assumes the form of 
an expectation of a personal experience. The force of 
the expectation will vary in general as the vividness 
and persistence of the mental image. Moreover, it 
follows, from what has been said, that this force of 
imagination will determine what little time-character 
we ever give to these wholly ungrounded illusions. 

We see, then, that any process of spontaneous imagi- 
nation will tend to beget some degree of illusory expec- 
tation. And among the agencies by which such un- 
grounded imagination arises, the promptings of feeling- 
play the most conspicuous part. A present emotional 
excitement may give to an imaginative anticipation, 



IMAGINATION AND EXPECTATION. 307 

such as that of the prophetic enthusiast, a reality which 
approximates to that of an actually perceived object. 
And even where this force of excitement is wanting, a 
gentle impulse of feeling may suffice to beget an as- 
surance of a distant reality. The unknown recesses of 
the remote future offer, indeed, the field in which the 
illusory impulses of our emotional nature have their 
richest harvest. 

" Thus, from afar, each dim discovered scene 
More pleasing seems than all the past hath been ; 
And every form, that Fancy can repair 
From dark oblivion, glows divinely there." 

The recurring emotions, the ruling aspirations, find 
objects for themselves in this veiled region. Feelings 
too shy to burst forth in unseemly anticipation of the 
immediate future, modestly satisfy themselves with 
this remote prospect of satisfaction. And thus, there 
arises the half-touching, half-amusing spectacle of men 
and women continually renewing illusory hopes, and 
continually pushing the date of their realization further 
on as time progresses and brings no actual fruition. 

So far I have spoken of such expectations as refer to 
future personal experience*only. Growing individual 
experience and the enlargement of this by the addition 
of social experience enable us to frame a number of 
other beliefs more or less similar to the simple expecta- 
tions just dealt with. Thus, for example, I can forecast 
with confidence events which will occur in the lives of 
others, and which I shall not even witness ; or again, 
I may even succeed in dimly descrying events, such 
as political changes or scientific discoveries, which 
will happen after my personal experience is at an end. 



308 ILLUSIONS OF BKLIEF. 

Once more, I can believe in something going on 
now at some distant and even inaccessible point of the 
universe, and this appears to involve a conditional 
expectation, and to mean that I am certain that I or 
anybody else would see the phenomenon, if we could 
at this moment be transported to the spot. 

All such previsions are supposed to be formed by a 
process of inference from personal experience, including 
the trustworthiness of testimony. Even allowing, how- 
ever, that this was so in the first stages of the belief, 
it is plain that, by dint of frequent renewal, the ex- 
pectation would soon cease to be a process of inference, 
and acquire an apparently self-evident character. This 
being so, if the expectation is not adequately grounded 
to start with, it is very likely to develop into an illusion. 
And it is to be added that these permanent anticipa- 
tions may have their origin much more in our own 
wishes or emotional promptings than in fact and ex- 
perience. The mind undisciplined by scientific training 
is wont to entertain numerous beliefs of this sort re- 
specting what is now going on in unvisited parts of the 
world, or what will happen hereafter in the distant 
future. The remote, and ' therefore obscure, in space 
and in time has always been the favourite region for 
the projection of pleasant fancies. 

Once more, besides these oblique kinds of expecta- 
tion, I may form other seemingly simple beliefs, to 
which the term expectation seems less clearly applic- 
able. Thus, on waking ia the morning and finding 
the ground covered with snow, my imagination moves 



QUASI-EXL'ECTATIOXS. 309 

backwards, as in the process of memory, and realizes 
the spectacle of the softly falling snow-flakes in the 
hours of the night. The oral communication of others' 
experience, including the traditions of the race, enables 
me to set out from any present point of time, and 
reconstruct complex chains of experience of vast 
length lying beyond the bounds of my own personal 
recollection. 

I need not here discuss what the exact nature of 
such beliefs is. J. S. Mill identifies them with ex- 
pectations. Thus, according to him, my belief in the 
nocturnal snowstorm is the assurance that I should 
have seen it had I waited up during the night. So my 
belief in Cicero's oratory resolves itself into the con- 
viction that I should have heard Cicero under certain 
conditions of time and place, which is identical with 
my expectation that I shall hear a certain speaker 
to-morrow if I go to the House of Commons. 1 How- 
ever this be, the thing to note is that such retrospective 
beliefs, when once formed, tend to approximate in 
character to recollections. This is true even of new 
beliefs in recent events directly made known by present 
objective consequences or signs, as the snowstorm. 
For in this case there is commonly no conscious 
comparison of the present signs with previously known 
signs, but merely a direct quasi-mnemonic passage of 
mind from the present fact to its antecedent. And 
it is still more true of long-entertained retrospective 
beliefs. When, for example, the original grounds of an 
historical hypothesis are lost sight of, and after the 

1 James Mill's Analysis of the Human Mind, edited by J. S. Mill, 
toI. i. p. 414, et seq. 



310 ILLUSIONS OF BELIEF. 

belief has hardened and solidified by time, it comes to 
look much more like a recollection than an expectation. 
As a matter of fact, we have seen, when studying the 
illusions of memory, that our personal experience does 
become confused with that of others. And one may 
say that all long-cherished retrospective beliefs tend 
to become assimilated to recollections. 

Here then, again, there seems to be room for 
illusion to arise. Even in the case of a recent pa^t 
event, directly made known by present objective signs, 
the mind is liable to err just as in the case of fore- 
casting an immediately approaching event. And such 
error has all the force of an illusion : its contradiction is 
almost as great a shock as that of a recollection. When, 
for example, I enter my house, and see a friend's card 
lying on the table, I so vividly represent to myself the 
recent call of my friend, that when I learn the card is 
an old one which has accidentally been put on the table, 
I experience a sense of disillusion very similar to that 
which attends a contradicted perception. The early 
crude stages of physical science abundantly illustrate 
the genesis of such illusions. 

It may be added that if there be any feeling present 
in the mind at the time, the barest suggestion of some- 
thing having happened will suffice to produce the 
immediate assurance. Thus, an angry person is apt to 
hastily accuse another of having done certain things on 
next to no evidence. The love of the marvellous seems 
to have played a conspicuous part in building up and 
sustaining the fanciful hypotheses which mark the 
dawn of physical science. 

Yerbal suggestion is a common mode of produc- 



QUASI-RECOLLEOTIONS. 311 

ing this semblance of a recollected event. By means 
of the narrative style, it vividly suggests the idea 
that the events described belong to the past, and ex- 
cites the imagination to a retrospective construction 
of them as though they were remembered events. 
Hence the power of works of fiction on the ordinary 
mind. Even when there is no approach to an illusion 
of perception, or to one of memory in the strict sense, 
the reading of a work of fiction begets at the moment 
a retrospective belief that has a certain resemblance to 
a recollection. 

All such illusions as those just illustrated, if not 
afterwards corrected, tend to harden into yet more dis- 
tinctly "intuitive" errors. Thus, for example, one of 
the crude geological hypotheses, of which Sir Charles 
Lyell tells us, 1 would, by the mere fact of being kept 
before the mind, tend to petrify into a hard fixed be- 
lief. And this process of hardening is seen strikingly 
illustrated in the case of traditional errors, especially 
when these fall in with our own emotional propensities. 
Our habitual representations of the remote historical 
past are liable to much the same kind of error as our 
recollections of early personal experience. The wrong 
statements of others and the promptings of our own 
fancies may lead in the first instance to a filling up 
of the remote past with purely imaginary shapes. 
Afterwards the particular origin of the belief is for- 
gotten, and the assurance assumes the aspect of a 
perfectly intuitive conviction. The hoary traditional 
myths respecting the golden age, and so on, and the 

1 Principles of Geology, ch. iii. 



312 ILLUSIONS OF BELIEF. 

persistent errors of historians under the sway of a strong 
emotional bias, illustrate such illusions. 

So much as to simple illusions of belief, or such 
as involve single representations only. Let uo now 
pass to compound illusions, which involve a complex 
group of representations. 

B. Compound Illusory Belief. 

A familiar example of a compound belief is the 
belief in a permanent or persistent individual object 
of a certain character. Such an idea, whatever its 
whole meaning may be — and this is a disputed point 
in philosophy — certainly seems to include a number 
of particular representations, corresponding to direct 
personal recollections, to the recollections of others, 
and to numerous anticipations of ourselves and of 
others. And if the object be a living creature endowed 
with feelings, our idea of it will contain, in addition 
to these represented perceptions of ourselves or of 
others, a series of represented insights, namely, such 
as correspond to the inner experience of the being, 
so far as this is known or imagined. 

It would thus seem that the idea which we 
habitually carry about with us respecting a complex 
individual object is a very composite idea. In order 
to see this more fully, let us inquire into what is 
meant by our belief in a person. My idea of a par- 
ticular friend contains, among other things, numbers 
of vague representations of his habitual modes of 
feeling and acting, and numbers of still more vague 
expectations of how ne will or might feel and act in 
certain circumstances. 



IDEAS OF PERMANENT THINGS. 313 

Now, it is plain that such a composite idea must 
have been a very slow growth, involving, in certain 
stages of its formation, numerous processes of inference 
or quasi-inference from the past to the future. But in 
process of time these elements fuse inseparably : the 
directly known and the inferred no longer stand apart 
in my mind ; my whole conception of the individual 
as he has been, is, and will be, seems one indivisible 
cognition ; and this cognition is so firmly fixed and 
presents itself so instantaneously to the mind when I 
think of the object, that it has all the appearance of 
an intuitive conviction. 

If this is a fairly accurate description of the struc- 
ture of these compound representations and of their 
attendant beliefs, it is easy to see how many openings 
for error they cover. To begin with, my representation 
of so complex a thing as a concrete personality must 
always be exceedingly inadequate and fragmentary. 
I see only a few facets of the person's many-sided 
mind and character. And yet, in general, I am not 
aware of this, but habitually identify my representa- 
tion with the totality of the object. 

More than this, a little attention to the process by 
which these compound beliefs arise will disclose the 
fact that this apparently adequate representation of 
another has arisen in part by other than logical pro- 
cesses. If the blending of memory and expectation 
were simply a mingling of facts with correct inferences 
from these, it might not greatly matter ; but it is 
something very different from this. Not only has 
our direct observation of the person been very limited, 
even that which we have been able to see has not 



314 ILLUSIONS OF BELIEF. 

been perfectly mirrored in our memory. It has already 
been remarked that recollection is a selective process, 
and this truth is strikingly illustrated in the growth 
of our enduring representations of things. What 
stamps itself on my memory is what surprised me or 
what deeply interested me at the moment. And then 
there are all the risks of mnemonic illusion to be 
taken into account as well. Thus, my idea of a person, 
so far even as it is built up on a basis of direct 
personal recollection, is essentially a fragmentary and 
to some extent a misleading representation. 

Nor is this all. My habitual idea of a person is 
a resultant of forces of memory conjoined with other 
forces. Among these are to be reckoned the in- 
fluence of illusory perception or insight, my own and 
that of others. The amount of misinterpretation of 
the words and actions of a single human being during 
the course of a long acquaintance must be very con- 
siderable. To these must be added the effect of erro- 
neous single expectations and reconstructions of past 
experiences, in so far as these have not been dis- 
tinctly contradicted and dissipated. All these errors, 
connected with single acts of observing or inferring 
the feelings and doings of another, have their effect 
in distorting the subsequent total representation of 
the person. 

Finally, we must include a more distinct ingredient 
of active illusion, namely, all the complex effects of 
the activity of imagination as led, not by fact and ex- 
perience, but by feeling and desire. Our permanent 
idea of another reflects all that we have fondly 
imagined the person capable of doing, and thus is 



OUB REPRESENTATIONS OF OTHERS. 315 

made up of an ideal as well as a real actually known 
personality. And this result of spontaneous imagina- 
tion must be taken to include the ideals entertained 
by others who are likely to have influenced us by their 
beliefs. 1 

Enough has probably been said to show how im- 
mensely improbable it is that our permanent cognition 
of so complex an object as a particular human being 
should be at all an accurate representation of the 
reality, how much of the erroneous is certain to get 
mixed up with the true. And this being so, we may 
say that our apparently simple direct cognition of a 
given person, our assurance of what he is and will 
continue to be, is to some extent illusory. 

Illusion of Self-Esteem. 

Let us now pass to another case of compound 
representation, where the illusory element is still more 
striking. I refer to the idea of self which each of 
us habitually carries about with him. Every man's 
opinion of himself, as a whole, is a very complex 
mental product, in which facts known by intro- 
spection no doubt play a - part, but probably only a 
very subordinate part. It is obvious, from what has 
been said about the structure of our habitual repre- 
sentations of other individuals, that our ordinary 
representation, of ourselves will be tinged with that 
mass of error which we have found to be connected 

1 To make this rough analysis more complete, I ought, perhaps, to 
include the effect of all the errors of introspection, memory, and spon- 
taneous belief, into which the person himself falls, in so far as they 
communicate themselves to others.' 



316 ILLUSIONS OF BELIEF. 

with single acts of introspection, recollectiong of past 
personal experience, and illusory single expectations of 
future personal experiences. How large an opening 
for erroneous conviction here presents itself can only 
be understood by a reference to certain deeply fixed 
impulses and feelings connected with the very con- 
sciousness of self, and favouring what I have marked 
off as active illusion. I shall try to show very briefly 
that each man's intuitive persuasion of his own powers, 
gifts, or importance — in brief, of his own particular 
value, contains, from the first, a palpable ingredient of 
active illusion. 

Most persons, one supposes, have with more or less 
distinct consciousness framed a notion of their own 
value, if not to the world generally, at least to them- 
selves. And this notion, however undefined it may 
be, is held to with a singular tenacity of belief. The 
greater part of mankind, indeed, seem never to enter- 
tain the question whether they really possess points of 
excellence. They assume it as a matter perfectly self- 
evident, and appear to believe in their vaguely con- 
ceived worth on the same immediate testimony of 
consciousness by which they assure themselves of their 
personal existence. Indeed, the conviction of personal 
consequence may be said to be a constant factor in 
most men's consciousness. However restrained by the 
rules of polite intercourse, it betrays its existence and 
its energy in innumerable ways. It displays itself 
most triumphantly when the mind is suddenly isolated 
from other minds, when other men unite in heaping 
neglect and contempt on the believer's head. In these 
moments he proves an almost heroic strength of con- 



CUE REPRESENTATIONS OF OURSELVES. 817 

fidence, believing in himself and in his claims to careful 
consideration when all his acquaintance are practically 
avowing their disbelief. 

The intensity of this belief in personal value may 
be observed in very different forms. The young 
woman who, quite independently of others' opinion, 
and even in defiance of it, cherishes a conviction that 
her external attractions have a considerable value ; the 
young man who, in the face of general indifference, 
persists in his habit of voluble talk on the supposition 
that he is conferring on his fellow-creatures the fruits 
of profound wisdom ; and the man of years whose 
opinion of his own social importance and moral worth 
is quite disproportionate to the estimation which others 
form of his claims — these alike illustrate the force and 
pertinacity of the belief. 

There are, no doubt, many exceptions to this form 
of self-appreciation. In certain robust minds, but 
little given to self-reflection, the idea of personal value 
rarely occurs. And then there are timid, sensitive 
natures that betray a tendency to self-distrust of all 
kinds, and to an undue depreciation of personal merit. 
Yet even here traces of an impulse to think well of 
self will appear to the attentive eye, and one can 
generally recognize that this impulse is only kept 
down by some other stronger force, as, for example, 
extreme sensitiveness to the judgment of others, great 
conscientiousness, and so on. And however this be, it 
will be allowed that the average man rates himself 
highly. 

It is to be noticed that this persuasion of personal 
value or excellence is, in common, very vague. A man 



318 ILLUSIONS OF BELIEF. 

may have a general sense of his own importance with- 
out in the least being able to say wherein exactly his 
superiority lies. Or, to put it another way, he may 
have a strong conviction that he stands high in the 
scale of morally deserving persons, and yet be unable 
to define his position more nearly. Commonly, the 
conviction seems to be only definable as an assurance 
of a superlative of which the positive and comparative 
are suppressed. At most, his idea of his moral altitude 
resolves itself into the proposition, " I am a good deal 
better than Mr. A. or Mr. B." Now, it is plain that in 
these intuitive judgments on his own excellence,, the 
man is making an assertion with respect, not only to 
inner subjective feelings which he only can be supposed 
to know immediately, but also to external objective 
facts which are patent to others, namely, to certain 
active tendencies and capabilities, to the direction of 
external conduct in certain lines. 1 Hence, if the 
assertion is erroneous, it will be in plain contradiction 
to others' perceptions of his powers or moral endow- 
ments. And this is what we actually find. A man's 
self-esteem, in a large preponderance of cases, is plainly 
in excess of others' esteem of him. What the man 
conceives himself to be differs widely from what others 
conceive him to be. 

" Oh wad some power the giftie gie us, 
To see oursels as others see us ! " 

Now, whence comes this large and approximately 
uniform discrepancy between our self-esteem and 

1 In the case of a vain woman thinking herself much more pretty 
than others think her, the error is still more obviously one connected 
with a belief in objective fact. 



ILLUSION OF SELF-ESTEEM. 319 

others' esteem of us? By trying to answer this 
question we shall come to understand still better the 
processes by which the most powerful forms of illusion 
are generated. 

It is, I think, a matter of every-day observation 
that children manifest an apparently instinctive dis- 
position to magnify self as soon as the vaguest idea of 
self is reached. It is very hard to define this feeling 
more precisely than by terming it a rudimentary sense 
of personal importance. It may show itself in very 
different ways, taking now a more active form, as an 
impulse of self-assertion, and a desire to enforce one's 
own will to the suppression of others' wills, and at 
another time wearing the appearance of a passive 
emotion, an elementary form of amour propre. And it 
is this feeling which forms the germ of the self-estima- 
tion of adults. For in truth all attribution of value 
involves an element of feeling, as respect, and of active 
desire, and the ascription of value to one's self is in 
its simplest form merely the expression of this state 
of mind. 

But how is it, it may be asked, that this feeling 
shows itself instinctively as soon as the idea of self 
begins to arise in consciousness ? The answer to this 
question is to be found, I imagine, in the general laws 
of mental development. All practical judgments like 
that of self-estimation are based on some feeling which 
is developed before it ; and, again, the feeling itself is 
based on some instinctive action which, in like manner, 
is earlier than the feeling. Thus, for example, an 
Englishman's judgment that his native country is of 
paramount value springs out of a long-existent senti- 



320 ILLUSIONS OF BELIEF. 

ment of patriotism, which sentiment again may be 
regarded as having slowly grown up about the half- 
blindly followed habit of defending and furthering 
the interests of one's nation or tribe. In a similar way, 
one suspects, the feeling of personal worth, with its 
accompanying judgment, is a product of a long process 
of instinctive action. 

What this action is it is scarcely necessary to 
remind the reader. Every living organism strives, or 
acts as if it consciously strove, to maintain its life 
and promote its well-being. The actions of plants 
are clearly related to the needs of a prosperous exist- 
ence, individual first and serial afterwards. The move- 
ments of the lower animals have the same end. Thus, 
on the supposition that man has been slowly evolved 
from lower forms, it is clear that the instinct of self- 
promotion must be the deepest and most ineradicable 
element of his nature, and it is this instinct which 
directly underlies the rudimentary sentiment of self- 
esteem of which we are now treating. 

This instinct will appear, first of all, as the unre- 
flecting organized habit of seeking individual good, 
of aiming at individual happiness, and so of pushing 
on the action of the individual will. This impulse 
shows itself in distinct form as soon as the individual 
is brought into competition with another similarly con- 
stituted being. It is the force which displays itself 
in all opposition and hostility, and it tends to limit 
and counteract the gregarious instincts of the race. 
In the next place, as intelligence expands, this in- 
stinctive action becomes conscious pursuit of an end, 
and at this stage the thing pursued attracts to itself 



OEIGIN OF SELF-ESTEEM. 321 

a sentiment. The individual now consciously desires 
his own happiness as contrasted with that of others, 
knowingly aims at enlarging his own sphere of action 
to the diminution of others' spheres. Here we have 
the nascent sentiment of self-esteem, on which all 
later judgments respecting individual importance are 
in part at least, founded. 

Thus, we see that long before man had arrived 
at an idea of self there had been growing up an 
emotional predisposition to think well of self. And 
in this way we may understand how it is that this 
sentiment of self-esteem shows itself immediately and 
instinctively in the child's mind as soon as its un- 
folding consciousness is strong enough to grasp the 
first rough idea of personal existence. Far down, so 
to speak, below the surface of distinct consciousness, 
in the intricate formation of ganglion-cell and nerve- 
fibre, the connections between the idea of self and 
this emotion of esteem have been slowly woven through 
long ages of animal development. 

Here, then, we seem to have the key to the appar- 
ently paradoxical fact that a man, with all his superior 
means of studying his own feelings, commonly esteems 
himself, in certain respects at least, less accurately 
than a good external observer would be capable of 
doing. In forming an opinion of ourselves we are ex- 
posed to the full force of a powerful impulse of feeling. 
This impulse, acting as a bias, enters more or less 
distinctly into our single acts of introspection, into 
our attempts to recall our past doings, into our in- 
sights into the meaning of others' words and actions 
as related to ourselves (forming the natural disposition 
15 



322 ILLUSIONS OF BELIEF. 

to enjoy flattery), and finally into our wild dreams 
as to our future achievements. It is thus the principal 
root of that gigantic illusion of self-conceit, which has 
long been recognized by practical sense as one of the 
greatest obstacles to social action ; and by art as one of 
the most ludicrous manifestations of human weakness. 

If there are all these openings for error in the 
beliefs we go on entertaining respecting individual 
things, including ourselves, there must be a yet 
larger number of such openings in those still more 
compound beliefs which we habitually hold respecting 
collections or classes of things. A single illusion of 
perception or of memory may suffice to give rise to a 
wholly illusory belief in a class of objects, for example, 
ghosts. The superstitious beliefs of mankind abundant! y 
illustrate this complexity of the sources of error. And 
in the case of our every-day beliefs respecting real 
classes of objects, these sources contribute a consider- 
able quota of error. We may again see this by examin- 
ing our ordinary beliefs respecting our fellow-men. 

A moment's consideration will show that our pre- 
vailing views respecting any section of mankind, say 
our fellow-countrymen, or mankind at large, correspond 
at best to a very loose process of reasoning. The 
accidents of our personal experience and opportunities 
of observation, the traditions which coloured our first 
ideas, the influence of our dominant feelings in selecting 
for attention and retention certain aspects of the com- 
plex object, and in idealizing this object, — these sources 
of passive and active illusion must, to say the least, 
have had as much to do with our present solidified and 
seemingly " intuitive " knowledge as anything that can 



ILLUSOEY VIEWS OF WOULD. 323 

be called the exercise of individual judgment and 
reasoning power. 

The force of this observation and the proof that 
such widely generalized beliefs are in part illusory, is 
seen in the fact that men of unlike experience and 
unlike temperament form such utterly dissimilar views 
of the same object. Thus, as Mr. Spencer has shown, 1 
in looking at things national there may be not only a 
powerful patriotic bias at work in the case of the 
vulgar Philistine, but also a distinctly anti-patriotic 
bias in the case of the over-fastidious seeker after 
culture. And I need hardly add. that the different 
estimates of mankind held with equal assurance by 
the cynic, the misanthropist, and the philanthropic 
vindicator of his species, illustrate a like diversity 
of the psychological conditions of belief. 

Finally, illusion may enter into that still wider 
collection of beliefs which make up our ordinary views 
of life and the world as a whole. Here there reflect 
themselves in the plainest manner the accidents of our 
individual experience and the peculiar errors to which 
our intellectual and emotional conformation disposes 
us. The world is for us what we feel it to be ; and we 
feel it to be the cause of our particular emotional ex- 
perience. Just as we have found that our environment 
helps to determine our idea of self and personal con- 
tinuity, so, conversely, our inner experience, our remem- 
bered or imagined joys and sorrows throw a reflection 
on the outer world, giving it its degree of worth. Hence 
the contradictory, and consequently to some extent at 
least illusory, views of the optimist and the pessimist, 

1 The Study of Sociology, ch. ix. 



324: ILLUSIONS OF BELIEF. 

" intuitions " which, I have tried to show elsewhere, 
are connected with deeply rooted habits of feeling, 
and are antecedent to all reasoned philosophic systems. 

If proof were yet wanted that these wide-embracing 
beliefs may to some extent be illusory, it would be 
found in the fact that they can be distinctly coloured 
by a temporary mood or mental tone. As I have 
more than once had occasion to remark, a feeling 
when present tends to colour all the ideas of the time. 
And when out of sorts, moody, and discontented, a man 
is prone to find a large objective cause of his dissatisfac- 
tion in a world out of joint and not moving to his mind. 

It is evident that all the permanent beliefs touched 
on in this chapter must constitute powerful predisposi- 
tions with respect to any particular act of perception, 
insight, introspection, or recollection. In other words, 
these persistent beliefs, so far as individual or personal, 
are but another name for those fixed habits of mind 
which, in the case of each one of us, constitute our 
intellectual bias, and the source of the error known as 
personal equation. And it may be added that, just as 
these erroneous beliefs existing in the shape of fixed 
prejudices constitute a bias to new error, so they act 
as powerful resisting forces in relation to new truth 
and the correction of error. 

In comparing these illusions of belief with those of 
perception and memory, we cannot fail to notice their 
greater compass or range, in other words, the greater 
extent of the region of fact misrepresented. Even if 
they are less forcible and irresistible than these errors, 
they clearly make up for this by the area which they 
cover. 



DIVERGENCE OV BELIEF. 325 

Another thing- to be observed with respect to these 
comprehensive beliefs is that where, as here, so many 
co-operant conditions are at work, the whole amount oi' 
common objective agreement is greatly reduced. In 
other words, individual peculiarities of intellectual con- 
formation, emotional temperament, and experience have 
a far wider scope for their influence in these beliefs 
than they have in the case of presentative cognitions. 
At the same time, it is noteworthy that error much 
more rapidly propagates itself here than in the case of 
our perceptions or recollections. As we have seen, 
these beliefs all include much more than the results of 
the individual's own experience. They offer a large 
field for the influence of personal ascendency, of the 
contagion of sympathy, and of authority and tradition. 
As a consequence of this, the illusions of belief are 
likely to be far more persistent than those of percep- 
tion or of memory ; for not only do they lose that 
salutary process of correction which comparison with 
the experience of others affords, but they may even 
be strengthened and upheld to some extent by such 
social influences. 

And here the question might seem to obtrude itself, 
whether, in relation to such a fluctuating mass of belief 
as that just reviewed, in which there appears to be so 
little common agreement, we can correctly speak of 
anything as objectively determinable. If illusion and 
error as a whole are defined by a reference to what is 
commonly held true and certain, what, it may be 
asked, becomes of the so-called illusions of belief? 

This question will have to be fully dealt with in 
the following chapter. Here it may be sufficient to 



326 ILLUSIONS OF BELIEF. 

remark that amid all this apparent deviation of belief 
from a common standard of truth, there is a clear 
tendency to a rational consensus. Thought, by dis- 
engaging what is really matter of permanent and 
common cognition, both in the individual and still 
more in the class, 1 and fixing this quantum of common 
cognition in the shape of accurate definitions and 
universal propositions, is ever fighting against and 
restraining the impulses of individual imagination 
towards dissociation and isolation of belief. And this 
same process of scientific control of belief is ever tend- 
ing to correct widespread traditional forms of error, 
and to erect a new and better standard of common 
cognition. 

This scientific regulation of belief only fails where 
the experiences which underlie the conceptions are 
individual, variable, and subjective. Hence there is 
no definite common conception of the value of life 
and of the world, just because the estimate of this 
value must vary with individual circumstances, tem- 
perament, etc. All that can be looked for here in the 
way of a common standard or norm is a rough average 
estimate. And this common-sense judgment serves 
practically as a sufficient criterion of truth, at least in 
relation to such extreme one-sidedness of view as 
approaches the abnormal, that is to say, one of the two 
poles of irrational exaltation, or "joy -madness," and 

1 As a matter of fact, the proportion of accurate knowledge to error 
is far larger in the case of classes than of individuals. Propositions 
with general terms for subject are less liable to be faulty than propo- 
sitions with singular terms for subject. 



CONVERGENCE OF BELIEF. 327 

abject melancholy, which appear among the phenomena 
of mental disease. 1 

1 For a description of each of these extremes of boundless gaiety 
and utter despondency, see Giiesinger, op. cit., Bk. III. ch. i. and ii. 
The relation of pessimism to pathological conditions is familiar 
enough ; less familiar is the relation of unrestrained optimism. Yet 
Griesinger writes that among the insane " boundless hilarity," with " a 
feeling of good fortune," and a general contentment with everything, 
is as frequent as depression and repining (see especially p. 281, also 
pp. 64, 65). 



CHAPTER XII. 

RESULTS. 

The foregoing study of illusions may not improbably 
have bad a bewildering effect on the mind of the 
reader. To keep the mental eye, like the bodily eye, 
for any time intently fixed on one object is apt to 
produce a feeling of giddiness. And in the case of a 
subject like illusion, the effect is enormously increased 
by the disturbing character of the object looked at. 
Indeed, the first feeling produced by our surrey of the 
wide field of illusory error might be expressed pretty 
accurately by the despondent cry of the poet — 

" Alas ! it is delusion all : 
The future cheats us from afar, 
Nor can we be what we recall, 
Nor dare we think on what we are." 

It must be confessed that our study has tended to 
bring home to the mind the wide range of the illusory 
and unreal in our intellectual life. In sense-percep- 
tion, in the introspection of the mind's own feelings, in 
the reading of others' feelings, in memory, and finally 
in belief, we have found a large field for illusory 
cognition. And while illusion has thus so great a 
depth in the individual mind, it has a no less striking 



RANGE OF ILLUSION. 329 

breadth or extent in the collective human mind. No 
doubt its grosser forms manifest themselves most con- 
spicuously in the undisciplined mind of the savage 
and the rustic ; yet even the cultivated mind is by no 
means free from its control. In truth, most of the 
illusions illustrated in this work are such as can be 
shared in by all classes of mind. 

In view of this wide far-reaching area of ascer- 
tained error, the mind naturally asks, What are the 
real limits of illusory cognition, and how can we be 
ever sure of having got beyond them ? This question 
leads us on to philosophical problems of the greatest 
consequence, problems which can only be very lightly 
touched in this place. Before approaching these, let 
us look back a little more carefully and gather up our 
results, reflect on the method which we have been 
unconsciously adopting, and inquire how far this 
scientific mode of procedure will take us in determin- 
ing what is the whole range of illusory cognition. 

We have found an ingredient of illusion mixed up 
with all the popularly recognized forms of imme- 
diate knowledge. Yet this ingredient is not equally 
conspicuous in all cases. First of all, illusion varies 
very considerably in its degree of force and persistence. 
Thus, in general, a presentative illusion is more coercive 
than a representative ; an apparent reality present to 
the mind is naturally felt to be more indubitable than 
one absent and only represented. On the other hand, 
a representative illusion is often more enduring than a 
presentative, that is to say, less easily found out. It 
is to be added that a good deal of illusion is only 
partial, there being throughout an under-current of 



33(j RESULTS. 

rational consciousness, a gentle play of self-criticism, 
which keeps the error from developing into a perfect 
self-delusion. This remark applies not only to the 
innocent illusions of art, but also to many of our 
every-day illusions, both presentative and representa- 
tive. In many cases, indeed, as, for example, in looking 
at a reflection in a mirror, the illusion is very imperfect, 
remaining in the nascent stage. 

Again, a little attention to the facts here brought 
together will show that the proportion of illusory to 
real knowledge is far from being the same in each 
class of immediate or quasi-immediate cognition. Thus, 
with respect to the great distinction between presenta- 
tive and representative knowledge, it is to be observed 
that, in so far as any act of cognition is, strictly speak- 
ing, presentative, it does not appear to admit of error. 
The illusions of perception are connected with the 
representative side of the process, and are numerous 
just because this is so extensive. On the other hand, 
in introspection, where the scope of independent repre- 
sentation is so limited, the amount of illusion is very 
inconsiderable, and may in practice be disregarded. 
So again, to take a narrower group of illusions, we 
find that in the recalling of distant events the pro- 
portion of error is vastly greater than in the recalling 
of near events. 

So much as to the extent of illusion as brought to 
light by our preceding study. Let us now glance at 
the conclusions obtained respecting its nature and its 
causes. 



CAUSES OF ILLUSION. 331 

Causes of Illusion. 

Looking at illusion as a whole, and abstracting 
from the differences of mental mechanism in the pro- 
cesses of perception, memory, etc., we may say that 
the rationale or mode of genesis of illusion is very 
much the same throughout. Speaking broadly, one 
may describe all knowledge as a correspondence of 
representation with fact or experience, or as a stable 
condition of the representation which cannot be dis- 
turbed by new experiences. It does not matter, for 
our present purpose, whether the fact represented is 
supposed to be directly present, as in- presentative 
cognition ; or to be absent, either as something past or 
future, or finally as a " general fact," that is to say, the 
group of facts (past and future) embodied in a universal 
proposition. 1 

In general this accordance between our representa- 
tions and facts is secured by the laws of our intellectual 
mechanism. It follows from the principles of associa- 
tion that our simple experiences, external and internal, 
will tend to reflect themselves in perception, memory, 
expectation, and general belief, in the very time-con- 
nections in which they actually occur. To put it 
briefly, facts which occur together will in general be 
represented together, and they will be the more per- 
fectly co-represented in proportion to the frequency of 
this concurrence. 

1 It has been seen that, from a purely psychological point of view, 
even -what looks at first like pure presentative cognition, as, for ex- 
ample, the recognition of a present feeling of the mind, involves 
an ingredient of representation. 



332 EESULTS. 

Illusion, as distinguished from correct knowledge, 
is, to put it broadly, deviation of representation from 
fact. This is due in part to limitations and defects 
in the intellectual mechanism itself, such as the im- 
perfections of the activities of attention, discrimination, 
and comparison, in relation to what is present. Still 
more is it due to the control of our mental processes 
by association and habit. These forces, which are at 
the very root of intelligence, are also, in a sense, the 
originators of error. Through the accidents of our 
experience or the momentary condition of our repro- 
ductive power, representations get wrongly grouped 
with presentations and with one another; wrongly 
grouped, that is to say, according to a perfect or ideal 
standard, namely, that the grouping should always 
exactly agree with the order of experience as a whole, 
and the force of cohesion be proportionate to the number 
of the conjunctions of this experience. 

This great source of error has been so abundantly 
illustrated under the head of Passive Illusions that I 
need not dwell on it further. It is plain that a passive 
error of perception, or of expectation, is due in general to 
a defective grouping of elements, to a grouping which 
answers, perhaps, to the run of the individual's actual 
experience, but not to a large and complete common 
experience. 1 Similarly, an illusory general belief is 
plainly a welding together of elements (here concepts, 
answering to innumerable representative images) in 
disagreement with the permanent connections of ex- 
perience. Even a passive illusion of memory, in so 

1 See especially what was said about the rationale of illusions 
of perception, pp. 37, 38. 



RATIONALE OF ILLUSION. 333 

far as it involves a rearrangement of successive repre- 
sentations, shows the same kind of defect. 

In the second place, this incorrect grouping may 
be due, not to defects in attention and discrimination, 
combined with insufficiently grounded association, but 
to the independent play of constructive imagination 
and the caprices of feeling. This is illustrated in what 
I have called Active Illusions, whether the excited 
perceptions and the hallucinations of sense, or the 
fanciful projections of memory or of expectation. 
Here we have a force directly opposed to that of ex- 
perience. Active illusion arises, not through the im- 
perfections of the intellectual mechanism, but through 
a palpable interference with this mechanism. It is a 
regrouping of elements which simulates the form of 
a suggestion by experience, but is, in reality, the out- 
come of the individual mind's extra-intellectual im- 
pulses. 

We see, then, that, in spite of obvious differences 
in the form, the process in all kinds of immediate 
cognition is fundamentally identical. It is essentially 
a bringing together of elements, whether similar 
or dissimilar and associated by a link of contiguity, 
and a viewing of these as connected parts of a whole ; 
it is a process of synthesis. And illusion, in all its 
forms, is bad grouping or carelessly performed synthesis. 
This holds good even of the simplest kinds of error in 
which a presentative element is wrongly classed ; and 
it holds good of those more conspicuous errors of per- 
ception, memory, expectation, and compound belief, in 
which representations connect themselves in an order 
not perfectly answering to the objective order. 



334 RESULTS. 

This view of the nature and causes of illusion is 
clearly capable of being expressed in physical language. 
Bad grouping of psychical elements is equivalent to 
imperfect co-ordination of their physical, that is to say, 
nervous, conditions, imperfect in the evolutionist's 
sense, as not exactly according with external relations. 
So far as illusions of suggestion (passive illusions) 
are concerned, the error is connected with organized 
tendencies, due to a limited action of experience. 
On the other hand, illusions of preconception (active 
illusions) usually involve no such deeply fixed or per- 
manent organic connections, but merely a temporary 
confluence of nerve-processes. 1 The nature of the 
physical process is best studied in the case of errors of 
sense-perception. Yet we may hypothetically argue 
that even in the case of the most complex errors, as 
those of memory and of belief, there is implied a 
deviation in the mode of connection of nervous struc- 
tures (whether the connection be permanent or tem- 
porary) from the external order of facts. 

And now we are in a position to see whether illusion 
is ultimately distinguishable from other modes of 
error, namely, those incident to conscious processes 
of reasoning. It must have been plain to an attentive 
reader throughout our exposition that, in spite of our 
provisional distinction, no sharp line can be drawn 
between much of what, on the surface, looks like im- 
mediate knowledge, and consciously derived or inferred 
knowledge. On its objective side, reasoning may be 

1 I say " usually," because, as we have seen, there may sometimes 
be a permanent and even an inherited predisposition to active illusion 
in the individual temperament and nervous organization. 



ILLUSION AND FALLACY. 335 

roughly defined as a conscious transition of mind from 
certain facts or relations of facts to other facts or 
relations recognized as similar. According to this 
definition, a fallacy would be a hasty, unwarranted 
transition to new cases not identical with the old. 
And a good part of immediate knowledge is funda- 
mentally the same, only that here, through the ex- 
ceptional force of association and habit, the transition 
is too rapid to be consciously recognized. Conse- 
quently, illusion becomes identified at bottom with 
fallacious inference : it may be briefly described as 
collapsed inference. Thus, illusory perception and 
expectation are plainly a hasty transition of mind 
from old to new, from past to present, conjunctions of 
experience. 1 And, as we have seen, an illusory general 
belief owes its existence to a coalescence of represen- 
tations of known facts or connections with products 
of imagination which simulate the appearance of in- 
ferences from these facts. 

In the case of memory, in so far as it is not aided 

1 See what was said on the nature of passive illusions of sense 
(pp. 44, 68, 70, etc.). The logical character of illusion might be brought 
out by saying that it resembles the fallacy which is due to reasoning 
from an approximate generalization as though it were a universal truth. 
In thus identifying illusion and fallacy, I must not be understood to 
say that there is, strictly speaking, any such thing as an unconscious 
reasoning process. On the contrary, I hold that it is a contradic- 
tion to talk of any mental operation as altogether unconscious. I 
simply wish to show that, by a kind of fiction, illusion may be de- 
scribed as the result of a series of steps which, if separately unfolded 
to consciousness (as they no longer are), would correspond to those of 
a process of inference. The fact that illusion arises by a process of 
contraction out of conscious inference seems to justify this use of lan- 
guage, even apart from the fact that the nervous processes in the two 
cases are pretty certainly the same. 



S3 6 RESULTS. 

by reasoning from present signs, there seems to be 
nothing like a movement of inference. It is evident, 
indeed, that memory is involved in and underlies every 
such transition of thought. Illusions of memory illus- 
trate rather a process of wrong classing, that is to say, 
of wrongly identifying the present mental image with 
past fact, which is the initial step in all inference. In 
this way they closely resemble those slight errors of 
perception which are due to erroneous classing of sense- 
impressions. But since the intellectual process involved 
in assimilating mental elements is very similar to that 
implied in assimilating complex groups of such ele- 
ments, we may say that even in these simple kinds of 
error there is something which resembles a wrong 
classing of relations, something, therefore, which ap- 
proximates in character to a fallacy. 

By help of this brief review of the nature and 
causes of illusion, we see that in general it may be 
spoken of as deviation of individual from common 
experience. This applies to passive illusion in so for 
as it follows from the accidents of individual experience, 
and it still more obviously applies to active illusion as 
due to the vagaries of individual feeling and construc- 
tive imagination. We might, perhaps, characterize all 
illusion as partial view, partial both in the sense of 
being incomplete, and in the other sense of being that 
to which the mind by its peculiar predispositions in- 
clines. This being so, we may very roughly describe 
all illusion as abnormal. Just as hallucination, the 
most signal instance of illusion, is distinctly on the 
border-land of healthy and unhealthy mental life; 
just as dreams are in the direction of such unhealthy 



ERROR AS INDIVIDUAL. 837 

mental action ; so the lesser illusions of memory and so 
on are abnormal in the sense that they imply a 
departure from a common typical mode of intellectual 
action. 

It is plain, indeed, that this is the position we have 
been taking up throughout our discussion of illusion. 
We have assumed that what is common and normal is 
true, or answers to what is objectively real. Thus, in 
dealing with errors of perception, we took for granted 
that the common percept — meaning by this what is 
permanent in the individual and the general ex- 
perience — is at the same time the true percept. So 
in discussing the illusions of memory we estimated ob- 
jective time by the judgment of the average man, free 
from individual bias, and apart from special circum- 
stances favourable to error. Similarly, in the case of 
belief, true belief was held to be that which men in 
general, or in the long run, or on the average, hold 
true, as distinguished from what the individual under 
variable and accidental influences holds true. And 
even in the case of introspection we found that true 
cognition resolved itself into a consensus or agreement 
as to certain psychical facts. 

Criterion of Illusion. 

Now, it behoves us here to examine this assumption, 
with the view of seeing how far it is perfectly sound. 
For it may be that what is commonly held true does 
not in all cases strictly answer to the real, in which 
case our idea of illusion would have to be extended so 
as to include certain common beliefs. This question 
was partly opened up at the close of the last chapter. 



338 ' KESULTS. 

It will be found that the full discussion of it carries us 
beyond the scientific point of view altogether. For 
the present, however, let us see what can be said about 
it from that standpoint of positive science to which we 
have hitherto been keeping. 

Now, if by common be meant what has been shared 
by all minds or the majority of minds up to a particu- 
lar time, a moment's inspection of the process of 
correcting illusion will show that science assumes the 
possibility of a common illusion. In the history of 
discovery, the first assault on an error was the setting 
up of the individual against the society. The men 
who first dared to say that the sun did not move round 
the earth, found to their cost what it was to fly in the 
face of a common, though illusory, perception of the 
senses. 1 

If, however, by common be understood what is 
permanently and unshakably held true by men in 
proportion as their minds become enlightened, then 
science certainly does assume the truth of common 
perception and belief. Thus, the progress of the phy- 
sical sciences may be described as a movement towards 
a new, higher, and more stable consensus of ideas and 
beliefs. In point of fact, the truths accepted by men 
of science already form a body of common belief for 

1 If we turn from the region of physical to that of moral ideas, 
we see this historical collision hetween common and individual con- 
viction in a yet more impressive form. The teacher of a new moral 
truth has again and again been set down to be an illusionist by a 
society which was itself under the sway of a long-reigning error. 
As George Eliot observes, " What we call illusions are often, in truth, 
a wider vision of past and present realities — a willing movement of a 
man's soul with the larger sweep of the world's forces." 



TKUTR AS COMMON. 339 

those who are supposed by all to have the means of 
testing the value of their convictions. And the same 
applies to the successive improvements in the concep- 
tions of the moral sciences, for example, history and 
psychology. Indeed, the very meaning of science 
appears to be a. body of common cognition to which 
all minds converge in proportion to their capabilities 
and opportunities of studying the particular subject- 
matter concerned. 

Not only so, from a strictly scientific point of 
view it might seem possible to prove that common 
cognition, as defined above, must in general be true 
cognition. I refer here to the now familiar method of 
the evolutionist. 

According to this doctrine, which is a scientific 
method in so far as it investigates the historical de- 
velopments of mind or the order of mental phenomena 
in time, cognition may be viewed as a part of the result 
of the interaction of external agencies and the organism, 
as an incident of the great process of adaptation, phy- 
sical and psychical, of organism to environment. In 
thus looking at cognition, the evolutionist is making 
the assumption which all science makes, namely, that 
correct views are correspondences between internal 
(mental) relations and external (physical) relations, 
incorrect views disagreements between these relations. 
From this point of view he may proceed to argue that 
the intellectual processes must tend to conform to ex- 
ternal facts. All correspondence, he tells us, means 
fitness to external conditions and practical efficiency, 
all want of correspondence practical incompetence. 
Consequently, those individuals m whom the corre- 



340 RESULTS. 

spondence was more complete and exact would havo 
an advantage in the struggle for existence and so tend 
to be preserved. In this way the process of natural 
selection, by separately adjusting individual repre- 
sentations to actualities, would make them converge 
towards a common meeting-point or social standard of 
true cognition. That is to say, by eliminating or at 
least greatly circumscribing the region of individual 
illusion, natural selection would exclude the possibility 
of a persistent common illusion. 

Not only so, the evolutionist may say that this 
coincidence between common beliefs and true beliefs 
would be furthered by social as well as individual 
competition. A community has an advantage in the 
struggle with other communities when it is dis- 
tinguished by the presence of the conditions of 
effective co-operation* such as mutual confidence. 
Among these conditions a body of true knowledge 
seems to be of the first importance, since conjoint 
action always presupposes common beliefs, and, to be 
effective action, implies that these beliefs are correct. 
Consequently, it may be argued, the forces at work 
in the action of man on man, of society on the indi- 
vidual, in the way of assimilating belief, must tend, 
in the long run, to bring about a coincidence between 
representations and facts. Thus, in another way, 
natural selection would help to adjust our ideas to 
realities, and to exclude the possibility of anything 
like a permanent common error. 

Yet once more, according to Mr. Herbert Spencer, 
the tendency to agreement between our ideas and 
the environment would be aided by what he calls the 



EVOLUTIONIST'S VIEW OF EKKOR. 341 

direct process of adaptation. The exercise of a function 
tends to the development of that function. Thus, our 
acts of perception must become more exact by mere 
repetition. So, too, the representations and concepts 
growing out of perceptions must tend to approximate 
to external facts by the direct action of the environment 
on our physical and psychical organism ; for external 
relations which are permanent will, in the long ran, 
stamp themselves on our nervous and mentnl structure 
more deeply .and indelibly than relations which are 
variable and accidental. 

It would seem, from all this, that so long as we 
are keeping to the scientific point of view, that is to 
say, taking for granted that there is something ob- 
jectively real answering to our perceptions and con- 
ceptions, the question of the possibility of a universal 
or (permanently) common illusion does not arise. Yet 
a little more reflection will show us that it may arise 
in a way. So far as the logical sufficiency of the social 
consensus or common belief is accepted as scientifically 
proved, it is open to suspicion on strictly scientific 
grounds. The evolutionist's proof involves one or two 
assumptions which are not exactly true. 

In the first place, it is not strictly correct to say 
that all illusion involves a practical unfitness to cir- 
cumstances. At the close of our investigation of 
particular groups of illusion, for example, those of per- 
ception and memory, it was pointed out that many of 
the errors reviewed were practically harmless, being 
either momentary and evanescent, or of such a cha- 
racter as not to lead to injurious action. And now, 
by glancing back over the field of illusion as a whole j 



342 EESULTS. 

we may see the same thing. The day-dreams in which 
some people are apt to indulge respecting the remote 
future have little effect on their conduct. So, too, a 
man's general view of the world is often unrelated to 
his daily habits of life. It seems to matter exceedingly 
little, in general, whether a person take up the geo- 
centric or the heliocentric conception of the cosmic 
structure, or even whether he adopt an optimistic or 
pessimistic view of life and its capabilities. 

So inadequate, indeed, does the agency of natural 
selection seem to be to eliminate illusion, that it may 
even be asked whether its tendency may not be 
sometimes to harden and fix rather than to dissolve 
and dissipate illusory ideas and beliefs. It will at 
once occur to the reader that the illusion of self-esteem, 
discussed in the last chapter, may have been highly 
useful as subserving individual self-preservation. In 
a similar way, it has been suggested by Schopenhauer 
that the illusion of the lover owes its force and his- 
torical persistence to its paramount utility for the pre- 
servation of the species. And to pass from a recurring 
individual to a permanently common belief, it is main- 
tained by the same pessimist and his followers that 
what they regard as the illusion of optimism, namely, 
the idea that human life as a whole is good, grows out 
of the individual's irrational love of life, which is only 
the same instinctive impulse of self-preservation ap- 
pearing as conscious desire. Once more, it has been 
suggested that the belief in free-will, even if illusory, 
would be preserved by the process of evolution, owing 
to its paramount utility in certain stages of moral 
development. All this seems to show at least the 



HARMLESS ILLUSIONS. 343 

possibility of a kind of illusion which would tend to 
perpetuate itself, and to appear as a permanent common 
belief. 

Now, so far as this is the case, so far as illusion is 
useful or only harmless, natural selection cannot, it is 
plain, be counted on to weed it out, keeping it within 
the narrow limits of the exceptional and individual. 
Natural selection gets rid of what is harmful only, and 
is indifferent to what is practically harmless. 

It may, however, still be said that the process of 
direct adaptation must tend to establish such a con- 
sensus of true belief. Now, I do not wish for a moment 
to dispute that the growth of intelligence by the con- 
tinual exercise of its functions tends to such a con- 
sensus : this is assumed to be the case by everybody. 
What I want to point out is that there is no scientific 
proof of this position. 

The correspondence of internal to external relations 
is obviously limited by the modes of action of the 
environment on the organism, consequently by the 
structure of the organism itself. Scientific men are 
familiar with the idea that there may be forces in the 
environment which are practically inoperative on the 
organism, there being no corresponding mode of sensi- 
bility. And even if it be said that our present know- 
ledge of the material world, including the doctrine 
of the conservation of energy, enables us to assert that 
there is no mode of force wholly unknown to us, it 
can still be contended that the environment may, for 
aught we know, be vastly more than the forces of which, 
owing to the nature of our organism, we know it to be 
composed. In short, since, on the evolution theory 



344 EESULTS. 

viewed as a scientific doctrine, the real external world 
does not directly mirror itself in our minds, but only in- 
directly brings our perceptions and representations into 
adjustment by bringing into adjustment the nervous 
organism with which they are somehow connected, it 
is plain that we cannot be certain of adequately appre- 
hending the external reality which is here assumed 
to exist. 

Science, then, cannot prove, but must assume the 
coincidence between permanent common intuitions and 
objective reality. To raise the question whether this 
coincidence is perfect or imperfect, whether all common 
intuitions known to be persistent are true or whether 
there are any that are illusory, is to pass beyond the 
scientific point of view to another, namely, the philo- 
sophic. Thus, our study of illusion naturally carries 
us on from scientific to philosophic reflection. Let me 
try to make this still more clear. 

Transition to Philosophic View. 

All science makes certain assumptions which it 
never examines. Thus, the physicist assumes that 
when we experience a sensation we are acted on by 
some pre-existing external object which is the cause, 
or at least one condition, of the sensation. While 
resolving the secondary qualities of light, sound, etc., 
into modes of motion, while representing the object 
very differently from the unscientific mind, he agrees 
with this in holding to the reality of something ex- 
ternal, regarding this as antecedent to and therefore as 
independent of the particular mind which receives the 
sense-impression. Again, he assumes the uniformity 



COMMON INTUITIONS CHALLENGED. 345 

of nature, the universality of the causal relation, and 
so on. 

Similarly, the modern psychologist, when confining 
himself within the limits of positive science, and treat- 
ing mind phenomenally or empirically, or, in other 
words, tracing the order of mental states in time and 
assigning their conditions, takes for granted much the 
same as physical science does. Thus, as our foregoing 
analysis of perception shows, he assumes that there is an 
external cause of our sensations, that there are material - 
bodies in space, which act on our sense-organs and so 
serve as the condition of our sense-impressions. More 
than this, he regards, in the way that has been illus- 
trated in this work, the percept itself, in so far as it 
is a process in time, as the normal result of the action 
of such external agents on our nerve-structures, in 
other words, as the effect of such action in the case 
of the healthy and perfect nervous organism with the 
average organized dispositions, physical and psychical ; 
in which case he supposes the percept to correspond, 
in certain respects at least, with the external cause 
as made known by physical science. And, on the 
other hand, he looks on a false or illusory percept as 
arising in another way not involving, as its condition, 
the pre-existence of a corresponding material body or 
physical agent. And in this view of perception, as of 
other mental phenomena, the psychologist clearly takes 
for granted the principle that all mental events con- 
form to the law of causation. Further, he assumes 
that the individual mind is somehow, in a way which 
it is not his province to inquire into, one and the same 
throughout, and so on. 
16 



346 RESULTS. 

The doctrine of evolution, too, in so far as scientific 
■ — that is, aiming at giving an account of the historical 
and pre-historical developments of the collective mind 
in time — agrees with psychology in making like as- 
sumptions. Thus, it conceives an external agency 
(the environment) as the cause of our common sensa- 
tions and perceptions. That is to say, it represents 
the external world as somehow antecedent to, and so 
apparently independent of, the perceptions which are 
adjusted to it. And all this shows that science, while 
removed from vulgar unenlightened opinion, takes 
sides with popular thought in assuming the truth of 
certain fundamental ideas or so-called intuitive beliefs, 
into the exact meaning of which it does not inquire. 

When the meaning of these assumptions is 
investigated, we pass out of the scientific into the 
philosophic domain. Philosophy has to critically in- 
vestigate the data of popular thought and of science. 
It has to discover exactly what is implied in these 
fundamental principles. Then it has to test their 
value by erecting a final criterion of truth, by probing 
the structure of cognition to the bottom, and deter- 
mining the proper organ of certain or accurate know- 
ledge ; or, to put it another way, it has to examine 
what is meant by reality, whether there is anything 
real independently of the mind, and if so, what. In 
doing this it inquires not only what common sense 
means by its object-world clothed in its variegated 
garment of secondary qualities, its beauty, and so on, 
but also what physical science means by its cosmic 
mechanism of sensible and extra-sensible matter in 
motion : whether there is any kind of objective reality 



SCIENCE AND PHILOSOPHY. 347 

belonging to the latter which does not also belong to 
the former ; and how the two worlds are related one to 
another. That is to say, he asks whether the bodies 
in space assumed to exist by the physicist as the ante- 
cedent conditions of particular sensations and percepts 
are independent of mind and perception generally. 1 

In doing all this, philosophy is theoretically free to 
upset as much of popular belief of the persistent kind 
as it likes. Nor can science find fault with it so long 
as it keeps to its own sphere, and does not directly con- 
tradict any truth which science, by the methods proper 
to it, is able to establish. Thus, for example, if 
philosophy finds that there is nothing real inde- 
pendently of mind, science will be satisfied so long as 
it finds a meaning for its assumed entities, such as 
space, external things, and physical causes. 2 

The student of philosophy need not be told that 
these imposing-looking problems respecting cognition, 
making up what the Germans call the "Theory of 
Cognition," and the cognate problem respecting the 
nature of reality, are still a long way from being settled. 
To-day, as in the days of Plato and Aristotle, are 
argued, in slightly altered forms, the vexed questions, 
What is true cognition ? Is it a mere efflux from 



1 To make this account of the philosophic problem of the object- 
world complete, I ought to touch not only on the distinction between 
the vulgar and the scientific view of material things, but also on the 
distinction, within physical science, between the less and the more 
abstract view roughly represented by molar and molecular physics. 

2 For an excellent account of the distinction between the scientific 
rnd the philosophic point of view, see Mr. Shadworth Hodgson's 
Philosophy of Reflection, Bk. I. chs. i. and iii. ; also Bk. III. chs. vii. 
and viii. 



348 RESULTS. 

sensation, a passive conformity of representation to 
sensation (sensualism or empiricism) ? or is it, on the 
other hand, a construction of active thought, involv- 
ing certain necessary forms of intelligence (rationalism 
or intuitivism) ? 

Again, how are we to shape to ourselves real 
objective existence ? Is it something wholly inde- 
pendent of the mind (realism) ? and if so, is this 
known to be what we — meaning here common people 
and men of science alike — represent it as being (natural 
realism), or something different (transfigured realism) ? 
Or is it, on the contrary, something involving mind 
(idealism) ? and if so, is it a strictly phenomenal dis- 
tinction within our conscious experience (empirical 
idealism, phenomenalism), or one of the two poles 
of subject and object constituted by every act of 
thought (rational idealism) ? These are some of the 
questions in philosophy which still await their final 
answer. 

Philosophy being thus still a question and not a 
solution, we need not here trouble ourselves about its 
problems further than to remark on their close con- 
nection with our special subject, the study of illusion. 

Our brief reference to some of the principal inquiries 
of philosophy shows that it tends to throw doubt on 
things which the unreflecting popular mind holds to 
be indubitable. Different schools of philosophy have 
shown themselves unequally concerned about these so- 
called intuitive certainties. In general it may be said 
that philosophy, though, as I have remarked, theo- 
retically free to set up its own standard of certainty, 
has in practice endeavoured to give a meaning to, 



WHAT IS REALITY? 319 

and to find a justification for the assumptions or first 
principles of science. On the other hand, it has not 
hesitated, when occasion required, to make very light 
of the intuitive beliefs of the popular mind as 
interpreted by itself. Thus, rationalists of the Platonic 
type have not shrunk from pronouncing individual 
impressions and objects illusory, an assertion which 
certainly seems to be opposed to the assumptions of 
common sense, if not to those of science. On the 
other hand, the modern empirical or association school 
is quite ready to declare that the vulgar belief in 
an external world, so far as it represents this as inde- 
pendent of mind, 1 is an illusion ; that the so-called 
necessary beliefs respecting identity, uniformity, causa- 
tion, etc., are not, strictly speaking, necessary ; and so 
on. And in these ways it certainly seems to come 
into conflict with popular convictions, or intuitive cer- 
tainties, as they present themselves to the unreflecting 
intelligence. 

Philosophy. seems, then, to be a continuation of that 
process of detecting illusion with which science in 
part concerns itself. Indeed, it is evident that our 

1 I hold, in spite of Berkeley's endeavours to reconcile bis position 
with that of common sense, that the popular view does at least tend 
in this direction. That is to say, the every-day habit, when consider- 
ing the external world, of abstracting from particular minds, leads on 
insensibly to that complete detachment of it from mind in general 
which expresses itself in the first stage of philosophic reflection, crude 
realism. The physicist appears to me, both from the first essays in Greek 
"nature-philosophy," as also from the not infrequent confusion even 
to-day between a perfectly safe "scientific materialism" and a highly 
questionable philosophic materialism, to share in this tendency to take 
separate consideration for separate existence. Each new stage of 
abstraction in physical science gives birth to a new attempt to find an 
independent reality, a thing-in-itself, hidden further away from sense 



350 RESULTS. 

special study has a very close connection with the 
philosophic inquiry. What philosophy wants is some- 
thing intuitively certain as its starting-point, some 
point d'appui for its construction. The errors incident 
to the process of reasoning do not greatly trouble it, 
since these can, in general, be guarded against by the 
rules of logic. But error in the midst of what, on the 
face of it, looks like intuitive knowledge naturally 
raises the question, Is there any kind of absolutely 
certain cognition, any organ for the accurate perception 
of truth ? And this intimate relation between the 
scientific and the philosophic consideration of illusion 
is abundantly illustrated in the history of philosophy. 
The errors of sense, appearing in a region which to 
the vulgar seems so indubitable, have again and again 
set men thinking on the question, " What is the 
whole range of illusion ? Is perception, as popularly 
understood, after all, a big hallucination ? Is our life a 
dream?" 1 

On the other hand, if our study of the wide range 
of illusion is fitted to induce that temper of mind 
which is said to be the beginning of philosophy, that 
attitude of universal doubt expressed by Descartes in 
his famous maxim, De omnibus dubitandum, a con- 
sideration of the process of correction is fitted to lead 
the mind on to the determination of the conditions of 
accurate knowledge. It is evident, indeed, that the 
very conception of an illusion implies a criterion of 
certainty : to call a thing illusory, is to judge it by re- 
ference to some accepted standard of truth. 

1 See the interesting autobiographical record of the growth of 
philosophic doubt in the Premiere Meditation of Descartes. 



CORRECTION OF ILLUSION. 351 

The mental processes involved in detecting, resist- 
ing, and overcoming illusion, are a very interesting 
subject for the psychologist, though we have not space 
here to investigate them fully. Turning to presenta- 
tive, and more particularly sense-illusions, we find that 
the detection of an illusion takes place now by an 
appeal from one sense to another, for example, from 
sight to touch, by way of verification ; x now (as in 
Myer's experiment) by a reference from sense and 
presentation altogether to representation or remem- 
bered experience and a process of reasoning ; and now, 
(as in the illusions of art) conversely, by a transition 
of mind from what is suggested to the actual sense- 
impression of the moment. In the sphere of me- 
mory, again, illusion is determined, as such, now by 
attending more carefully to the contents of memory, 
now by a process of reasoning from some presentative 
cognition. Finally, errors in our comprehensive 
general representations of things are known to be such 
partly by reasoning from other conceptions, and partly 
by a continual process of reduction of representation 
to presentation, the general to the particular. I may 
add that the correction of illusion by an act of re- 
flection and reasoning, which brings the part into 
consistent relation with the whole of experience, 
includes throughout the comparison of the individual 
with the collective or social experience. 2 

1 The appeal is not, as we have seen, invariably from sight to touch, 
but may be in the reverse direction, as in the recognition of the 
duality of the points of a pair of compasses, which seem one to the 
tactual sense. 

2 I might further remark that this " collective experience " includes 
previously detected illusions of ourselves and of others. 



352 RESULTS. 

We may, perhaps, roughly summarize these opera- 
tions by saying that they consist in the control of the 
lower automatic processes (association or suggestion) 
by the higher activities of conscious will. This activity 
of will takes the form now of an effort of attention to 
what is directly present to the mind (sense-impression, 
internal feeling, mnemonic image, etc.), now of con- 
scious reflection, judgment, and reasoning, by which the 
error is brought into relation to our experience as a 
whole, individual and collective. 

It is for the philosopher to investigate the inmost 
nature of these operations as they exhibit themselves 
in our every-day individual experience, and in the 
large intellectual movements of history. In no better 
way can he arrive at what common sense and science 
regard as certain cognition, at the kinds of knowledge 
on which they are wont to rely most unhesitatingly. 

There is one other relation of our subject to philo- 
sophic problems which I have purposely left for final 
consideration. Our study has consisted mainly in the 
psychological analysis of illusions supposed to be known 
or capable of being known as such. Now, the modern 
association school professes to -be able to resolve some 
of the so-called intuitions of common sense into ele- 
ments exactly similar to those into which we have 
here been resolving what are acknowledged by all as 
illusions. This fact would seem to point to a close 
connection between the scientific study of illusion and 
the particular view of these fundamental intuitions 
taken by one philosophic school. In order to see 
whether there is really this connection, we must reflect 



PSYCHOLOGY AS SCIENCE. 353 

a little furtlier on the nature of the method which we 
have been pursuing. 

I have already had occasion to use the expression 
" scientific psychology," or psychology as a positive 
science, and the meaning of this expression must now 
be more carefully considered. As a positive science, 
psychology is limited to the function of analyzing 
mental states, and of tracing their origin in previous 
and more simple mental states. It has, strictly speak- 
ing, nothing to do with the question of the legitimacy 
or validity of any mental act. 

Take a percept, for example. Psychology can trace 
its parentage in sensation, the mode in which it has 
come by its contents in the laws of association. But 
by common consent, a percept implies a presentative 
apprehension of an object now present to sense. Is 
this valid or illusory ? This question psychology, as 
science, does not attempt to answer. It would not, I 
conceive, answer it even if it were able to make out 
that the whole mental content in the percept can be 
traced back to elementary sensations and their combi- 
nations. For the fact that in the chemistry of mind 
elements may combine in perfectly new forms does not 
disprove that the forms thus arising, whether senti- 
ments or quasi-cognitions, are invalid. Much less can 
psychology dispute the validity of a percept if it cannot 
be sure that the mind adds nothing to sensation and 
its grouping ; that in the genesis of the perceptive state, 
with its intuition of something external and now pre- 
sent as object, nothing like a form of intelligence is 
superimposed on the elements of sensation, giving to 
the result of their coalescence the particular unity 



354 RESULTS. 

which we find. Whether psychology as a positive 
science can ever be sure of this : whether, that is to 
say, it can answer the question, " How do we come by 
the idea of object?" without assuming some particular 
philosophic or extra-scientific theory respecting the 
ultimate nature of mind, is a point which I purposely 
leave open. 

I would contend, then, that the psychologist, in 
tracing the genesis of the percept out of previous 
mental experiences, no more settles the question, What 
is the object of perception ? than the physicist settles 
it in referring the sense-impression (and so the percept) 
to a present material agent as its condition. 

The same applies to our idea of self. I may dis- 
cover the concrete experiences which supply the filling 
in of the idea, and yet not settle the question, Does in- 
telligence add anything in the construction of the 
form of this idea? and still less settle the question 
whether there is any real unity answering to the 
idea. 

If this is a correct distinction, if psychology, as 
science, does not determine questions of validity or 
objective meaning but only of genesis, if it looks at 
mental states in relation only to their temporal and 
causal concomitants and not to their objects, it must 
follow that our preceding analysis of illusion involves 
no particular philosophic theory as to the nature of 
intelligence, but, so far as accurate, consists of scientific 
facts which all philosophic theories of intelligence 
must alike be prepared to accept. And I have little 
doubt that each of the two great opposed doctrines, 
the intuitive and the associational, would claim to be 



PSYCHOLOGY AS PHILOSOPHY. 355 

in a position to take up these facts into its particular 
theory, and to view them in its own way. 

But in addition to this scientific psychology, there 
is another so-called psychology, which is, strictly 
speaking, philosophic. This, I need hardly say, is 
the association philosophy. It proceeds by analyzing 
certain cognitions and sentiments into their elements, 
and straightway declaring that they mean nothing 
more than these. That is to say, the associationist 
passes from genesis to validity, from the history of a 
conscious state to its objective meaning. Thus, from 
showing that an intuitive belief, say that in causation, 
is not original (in the individual or at least in the 
race), it goes on to assert that it is not a valid imme- 
diate cognition at all. Now, I am not concerned here 
to inquire into the logical value of this transition, but 
simply to point out that it is extra-scientific and dis- 
tinctly philosophic. If logically justifiable, it is so 
because of some plainly yjliiloso'pMe assumption, as that 
made by Hume, namely, that all ideas not derived 
from impressions are to this extent fictitious or illusory. 

And now we are in a position to understand the 
bearing of our scientific analysis of acknowledged 
illusions on the associationist's treatment of the alleged 
illusions of common sense. There is no doubt, I think, 
that some of the so-called intuitions of common sense 
have points of analogy to acknowledged illusions. For 
example, the conviction in the act of perception that 
something external to the mind and independent of it 
exists, has a certain superficial resemblance to an hallu- 
cination of sense ; and moreover, the associationist seeks 
to explain it by means of these very processes which 



356 RESULTS. 

underlie what is recognized by all as sense-illusion. 1 
Again, it may be said that our notions of force and of a 
causal nexus in the physical world imply the idea of 
conscious energy as known through our muscular 
sensations, and so have a suspicious resemblance to 
those anthropomorphic illusions of which I have spoken 
under Illusions of Insight. Once more, the conscious- 
ness of freedom may, as I have suggested, be viewed 
as analogous in its form and its mode of origin to 
illusions of introspection. As a last example, it may 
be said that the mind's certain conviction of the in- 
nateness of some of its ideas resembles those illusions 
of memory which arise through an inability to think 
ourselves back into a remote past having a type of 
consciousness widely unlike that of the present. 

But now, mark the difference. In our scientific 
analysis of popularly known illusions, we had something 
by which to determine the illusory character of the 
presentation or belief. We had a popularly or scien- 
tifically accepted standard of certainty, by a reference 
to which we might test the particular soi-disant cogni- 
tion. But in the case of these fundamental beliefs we 
have no such criterion, except we adopt some particular 
philosophic theory, say that of the associationist him- 
self. Hence this similarity in structure and origin 
cannot in itself be said to amount to a proof of equality 
of logical or objective value. Here again it must be 
remarked that origin does not carry validity or in- 
validity with it. 2 

1 M. Taine frankly teaches that what is commonly called accurate 
perception is a " true hallucination " {Be V Intelligence, 2ieme partie, 
Livre I. ch. i. sec. 3). 

2 It only seems to do so, apart from philosophic assumptions, in 



FUNDAMENTAL ILLUSIONS. 357 

We thus come back to our starting-point. While 
there are close relations, psychological and logical, 
between the scientific study of the ascertained facts of 
illusion and the philosophic determination of what is 
illusory in knowledge as a whole, the two domains 
must be clearly distinguished. On purely scientific 
ground we cannot answer the question, " How far does 
illusion extend ? " The solution of this question must 
be handed over to the philosopher, as one aspect of his 
problem of cognition. 

One or two remarks may, perhaps, be hazarded in 
concluding this account of the relation of the scientific 
to the philosophic problem of illusion. Science, as 
we have seen, takes its stand on a stable consensus, a 
body of commonly accepted belief. And this being so, 
it would seem to follow, that so far as she is allowed 
to interest herself in philosophic questions, she will 
naturally be disposed to ask, What beliefs are shared in 
by all minds, so far as normal and developed? In 
other words., she will be inclined to look at universality 

certain cases where experience testifies to a uniform untrustworthi- 
ness of the origin. For example, we may, on grounds of matter of 
fact and experience, be disposed to distrust any belief that we 
recognize as springing from an emotional source, from the mind's 
feelings and wishes. 

I may add that a so-called intuitive belief may refer to a matter of 
fact which can be tested by the facts of experience and by scientific 
methods. Thus, for example, the old and now exploded form of the 
doctrine of innate, ideas, which declared that children were born with 
certain ideas ready made, might be tested by observation of childhood, 
and reasoning from its general intellectual condition. The same 
applies to the physiological theories of space-perception, supposed to 
be based on Kant's doctrine, put forward in Germany by Johannes 
Miiller and the " nativistic school." (See my exposition and criticism 
of these doctrines in Mind, April, 1878, pp. 16S-178 and 193-195.) 



358 RESULTS. 

as the main thing to be determined in the region of 
philosophic inquiry. The metaphysical sceptic, fond 
of daring exploits, may break up as many accepted 
ideas as he likes into illusory debris, provided only he 
has some bit of reality left to take his stand on. 
Meanwhile, the scientific mind, here agreeing with 
the practical mind, will ask, "Will the beliefs thus 
said to be capable of being shown to be illusory ever 
cease to exercise their hold on men's minds, including 
that of the iconoclast himself ? Is the mode of demon- 
stration of such a kind . as to be likely ever to 
materially weaken the common-sense ' intuition ' ? " 

This question would seem to be most directly an- 
swerable by an appeal to individual testimony. Viewed 
in this light, it is a question for the present, for some 
few already allege that in their case philosophic reason- 
ings exercise an appreciable effect on these beliefs. 
And so far as this is so, the man of scientific temper 
will feel that there is a question for hirn. 

It is evident, however, that the question of the 
persistence of these fundamental beliefs is much more 
one for the future than for the present. The correction 
of a clearly detected illusion is, as I have more than 
once remarked, a slow process. An illusion such as the 
apparent movement of the sun will persist as a 
partially developed error long after it has been con- 
victed. And it may be that the fundamental beliefs 
here referred to, even if presumably illusory, are 
destined to exercise their spell for long ages yet. 

Whether this will be the case or not, whether these 
intuitive beliefs are destined slowly to decay and be 
dissolved as time rolls on, or whether they will retain 



PERSISTENCE OF INTUITIONS. 359 

an eternal youth, is a question which we of to-day seem, 
on a first view of the matter, to have no way of an- 
swering which does not assume the very point in 
question— the truth or falsity of the belief. This 
much may, however, be said. The associationist who 
resolves these erroneous intuitions into the play of 
association, admits that the forces at work generating 
and consolidating the illusory belief are constant and 
permanent forces, and such as are not likely to be less 
effective in the future than they have been in the past 
Thus, he teaches that the intuition of the single object 
in the act of perception owes its strength to " in- 
separable association," according to which law the 
ideas of the separate " possibilities of sensation," which 
are all we know of the object, coalesce in the shape 
of an idea of a single uniting substance. He adds, 
perhaps, that heredity has tended, and will still tend, 
to fix the habit of thus transforming an actual multi- 
plicity into an imaginary unity. And in thus arguing, 
he is allowing that the illusion is one which, to say 
the least of it, it will always be exceedingly difficult 
for reason to dislodge. 

In view of this uncertainty, and of the possibility, 
if not the probability, of these beliefs remaining as 
they have remained, at least approximately universal, 
the man of science will probably be disposed to 
hold himself indifferently to the question. He will be 
inclined to say, "What does it matter whether you 
call such an apparently permanent belief the cor- 
relative of a reality or an illusion? Does it make 
any practical difference whether a universal ' intui- 
tion,' of which we cannot rid ourselves, be described 



360 EESULTS. 

as a uniformly recurring fiction of the imagination, 
or an integral constitutive factor of intelligence? 
And, in considering the historical aspect of the ques- 
tion, does it not come to much the same thing whether 
such permanent mental products be spoken of as the 
attenuated forms or ghostly survivals of more sub- 
stantial primitive illusions (for example, anthropo- 
morphic representations of material objects, 'animistic' 
representations of mind and personality), or as the 
slowly perfected results of intellectual evolution ? " 

This attitude of the scientific mind towards philo- 
sophic problems will be confirmed when it is seen that 
those who seek to resolve stable common convictions 
into illusions are forced, by their very mode of demon- 
stration, to allow these intuitions a measure of validity. 
Thus, the ideas of the unity and externality attributed 
to the object in the act of perception are said by the 
associationist to answer to a matter of fact, namely, 
the permanent coexistence of certain possibilities of 
sensation, and the dependence of the single sensations 
of the individual on the presence of the most permanent 
of these possibilities, namely, those of the active or 
muscular and passive sensations of touch, \yhich are, 
moreover, by far the most constant for all minds. 
Similarly, the idea of a necessary connection between 
cause and effect, even if illusory in so far as it expresses 
an objective necessity, is allowed to be true as an ex- 
pression of that uniformity of our experience which all 
scientific progress tends to illustrate more and more 
distinctly. And even the idea of a permanent self, as 
distinct from particular fugitive feelings, is admitted 
by the associationist to be correct in so far as it ex- 



TRUTH AND INTELLECTUAL CONSENSUS. 301 ' 

presses the fact that mind is "a series of feelings 
which is aware of itself as past and future." In short, 
these "illusory intuitions," by the showing of those 
who affirm them to be illusory, are by no means hal- 
lucinations having no real object as their correlative, 
but merely illusions in the narrow sense, and illusions, 
moreover, in which the ratio of truth to error seems 
to be a large one. 

It would thus appear that philosophy tends, after 
all, to unsettle what appear to be permanent con- 
victions of the common mind and the presuppositions 
of science much less than is sometimes imagined. Our 
intuitions of external realities, our indestructible belief 
in the uniformity of nature, in the nexus of ctfuse 
and effect, and so on, are, by the admission of all 
philosophers, at least partially and relatively true; 
that is to say, true in relation to certain features of 
our common experience. At the worst, they can only 
be called illusory as slightly misrepresenting the exact 
results of this experience. And even so, the mis- 
representation must, by the very nature of the case, 
be practically insignificant. And so in full view of 
the subtleties of philosophic speculation, the man of 
science may still feel justified in regarding his standard 
of truth, a stable consensus of belief, as above 
suspicion. 



INDEX. 



A. 

A-bercrombie, Dr. J., 141, note ', 
278. 

Abnormal life, relation of, to nor- 
mal, 1, 120, 121, 124, 182, 277, 
284, note 1 , 336; effects of 
amputation, 62 ; modification of 
sensibility in, 65 ; gross sense- 
illusions of, 111, hallucinations 
of, 118 ; sense of personal iden- 
tity in, 289. 

Active, stage in perception, 27 ; 
illusion distinguished from pas- 
sive, 45, 332-334. 

Actor. See Theatre. 

Adaptation, illusion as want of, 
124, 188, 339. 

./Esthetic intuition, 213 ; illusions 
of, 214. 

After-dreams, 144, 183. 

After-sensation, after-impression, 
55, 115. 

Anaesthesia, 65. 

Ancestral experience, results of, 
281. 

Animals, recognition of portraits 
by, 105 ; expectation of, 298. 

Anthropomorphism, 225, 360. 

Anticipation. See Expectation. 

Apparitions. See Hallucination. 

Aristotle, 130. 

Art, illusions of, 77, 104. 

Artemidoros, 129. 



Association, laws of, in percep- 
tion, 22 ; in dreams, 153, 156 ; 
link of resemblance in dreams, 
159 ; associative dispositions in 
dreams, 169; effect of, in insight, 
221 ; inseparable, 359. 

Associationist, views of, 349, 352, 
355. 

Attention, involved in perception, 
21 ; absence of, in sense-illusion, 
39, 87 ; relation of, to recogni- 
tion of objects, iJO ; expectant, 
93 ; attitude of, in dreaming, 
137, 172; to internal mental 
states, 194; absence of, in 
errors of insight, 228. 

Authority, influence of, in intro- 
spection, 210 ; in belief, 325. 

Autobiography, errors connected 
with, 276, 280. 

Automatic activity of centres, in 
hallucinations, 113 ; in dreams, 
136,151; automatic intellectual 
processes, 300, 335, 352. 



Baillarger, J., 13, note 1 , 113, note ', 
119, notes * and 8 , 120, note '. 

Bain, Dr. A., 32, note ', 117, note 2 , 
190. 

Beattie, J., 141, note 1 . 

Beauty, sentiment of, 206, 213. 

Belief, immediate, 14, 15, 294 j 



364 



INDEX. 



simple and compound, 296 ; 
illusory forms of, 297; simple 
expectation, 297 ; expectation 
of extra-personal experiences, 
307 ; retrospective, 309 ; in 
persistent objects and persons, 
312 ; self-esteem, 315 ; repre- 
sentation of classes of things, 
322; representations of man- 
kind, 322 ; representation of 
life and the world as a whole, 
322 ; as predisposition to error, 
324; amount of divergence in, 
325 ; tendency towards con- 
vergence in, 326. 

Beneficial, correct .knowledge as, 
340 ; illusion as, 312. 

Berkeley, Bishop, 218, 349, note '. 

Binet, A., 53, note l . 

Boismont, Brierre de, 11, note '. 

Borner, J., 146. 

Braid, James, 186, 187. 

Brewster, Sir D., 42, 73, 81, 116. 

Briicke, E., 77, note l . 

Byron, Lord, 116. 

C. 

Carpenter, Dr. W. B., 32. note \ 
108, 110/note \ 186, 231, note 1 , 
265, note l , 276. 

Castle-building, as illusory per- 
ception, 3, 99. 

Cause, idea of, in science, 344 ; 
reality of relation of, 347, 349, 
356, 360. 

Change, a condition of conscious 
life, 252, 287, note K 

Childhood, our recollections of, 
263, 269. 

Children, curiosity of, 175, 180; 
estimate of time by, 256 ; con- 
fusion of dream and waking 
life by, 276 ; imagination of, 
279 ; self-assertion of, 319 ; 
intellectual condition of, 357, 
note l . 

Clarke, Dr. E. H., 117. 

Classification, in recognition of 
sensation, 21 ; in recognition of 



object, 24 ; in introspective 
recognition, 193. 

Clifford, Professor W. K, 56, 
note l . 

Coalescence, of sensations, 43, 52 ; 
of dream-images, 162 ; of inter- 
nal feelings, 196 ; of mnenionio 
images, 265. 

Coenaesthesis, 41, 99, 145, 286, 
288. 

Cognition, immediate or intuitive, 
5, 14-16, 294 ; presentative 
and representative, 9, 13, 217, 
330 ; nature of, in dreams, 168, 
172 ; natnre of, generally, 295, 
331 ; philosophic problems of, 
346. 

Colour, external reality of, 8, 37 ; 
illusory perception of, 37, 88 ; 
subjective complementary co- 
lours (colour-contrast), 67, S3. 

Coloured media, objects seen 
through, 82. 

Common cognition, and truth, 
337 ; genesis and validity of, 
353. 

Common experience distinguished 
from individual, 26, 27, 137, 
209. 214, 336, 351 ; illusion as, 
47, 325, 337. 

Common sense, intuitions of, 346, 
349, 352, 357. 

Complementary colours, 67, 83. 

Concave, apparent conversion of, 
into convex, S4. 

Conjuror, tricks of, 56, 106. 

Consciousness, veracity of, 192, 
205 ; inspection of phenomena 
of, 196 ; of self, 283, 285. 

Consensus, the standard of truth, 
7, 8, 211, 325, 338, 357. 

Conservation of energy, 343. 

Construction, rational, in dreams, 
170. 

Continuum, the perception of the 
world as, 52, 56, note 1 . 

Correction of illusion, in sense- 
illusion, 38, 124, 137; dreams, 
182 ; introspection, 210 ; in- 
sight, 229; memorv, 291; his. 



INDEX. 



365 



torical correction, 338 ; intel- 
lectual processes involved in, 
351. 

Criterion of illusion, 337. 

Cudworth, E., 161 

D. 

Deception of the senses, 19 ; 
self-deception, 200 ; conscious 
deception of others, 222. 

Delboeuf, J., 175, note », 235, 
note l . 

Delirium tremens, 118, note 2 . 

Democritus, 130. 

De Quincey, 253, 280. 

Descartes, K,., 116, 350. 

Dickens, Charles, 277. 

Direction, illusory sense of, in 
vision, 66, 71, 73 ; in hearing, 
72, 75. 

Disease. See Abnormal life. 

Dissolution. See Evolution. 

Doubt, starting-point in philo- 
sophy, 350. 

Dreams, relation of, to illusions 
of sense, 18, 130 ; and waking 
experience, 127 ; theories of, 
128 ; physiology of, 131 ; extent 
of, in sleep, 132 ; psychological 
conditions of, 136 ; excitants of, 
139, 143 ; exaggeration in, 147 ; 
symbolism of, 149; as results 
of automatic activity of centres, 
151 ; as results of association, 
153; structure of, 156; in- 
coherent, 156 ; coherent, 161 ; 
action of feeling in, 164 ; play 
of associative dispositions in, 
168 ; co-operation of attention 
and intelligence in, 172 ; limits 
of intelligence in, 180 ; after- 
dreams, 183, 274 ; relation of, 
to hypnotic condition, 185 ; 
experience of, in relation to 
errors of memory, 273. 

B. 

Eccentricity, law of, 59. 
Ego. See Self. 



Emotion, and illusion of percep- 
tion, 103 ; and hallucination, 
115 ; and bodily sensations, 
150 ; control of dreams by, 164 ; 
introspection of, 199 ; and illu- 
sion of introspection, 203 ; and 
aesthetic intuition, 213 ; and illu- 
sion of memory, 270 ; and illu- 
sion of belief, 306, 324 ; and 
cognition generally, 357, note '. 

Empiricism, philosophic, 348. 

Ennui, and sense of time, 250. 

Environment, sources of sense- 
illusion in, 47, 48, 70 ; view of, 
in mental disease, 290, 326 ; 
view of, in normal life, 323 ; 
action of, in assimilating belief, 
339. 

Error, immediate and mediate, 6, 
334. 

Esquirol, J. E. D., 12, note 2 . 

Evolution, relation of, to dissolu- 
tion, 122; of power of introspec- 
tion, 209 ; of power of insight, 
230 ; and self-assertion, 320 ; 
evolutionist's view of error, 
339 ; doctrine of, as science, 
346. 

Exaggeration, in interpretation of 
sensations, 65 ; in dream-in- 
terpretation, 147 ; in memory, 
269. 

Expectation, preliminary to per- 
ception, 30 ; and illusory per- 
ception, 93, 102, 106 ; nature of, 
295 ; and memory, 298 ; of new 
experience, 301 ; of remote 
events, 302 ; measurement of 
duration in, 302 ; action of 
imagination in, 305 ; extension 
of meaning of, 307, 308. 

Experience, effect of, in percep- 
tion, 22, 68, 85, 86, 91 ; external 
and internal, 194, 210 ; revivals 
of waking, in dreams, 152; 
effects of present, on retrospec- 
tion, 267 ; anticipation of new> 
301. 

External world. See World- 



300 



INDEX. 



F. 

Fallacy and illusion, 6, 335 j of 

testimony, 265. 
Familiarity, sense of, in new 

objects, 272, 281. 
Fechner, G. T., 51. 
Ferrier, Dr., 32, note *, 58, note *. 
Fiction, as producing illusion, 

278, 279, 311. 
Fitness. See Adaptation. 
Flattery, rationale of, 200, 222. 
Forgetl'ulness and illusion, 278, 

279 311. 
Free-will, doctrine of, 207, 342, 

356. 
Future. See Expectation 



Galton, F., 117. 

Ghosts. See .Hallucination. 

Goethe, 116, 117, 280 and note \ 

Griesiuger, W., 13, note ',63, note l , 
66, note l , 115, 118, note 2 , 
119, note \ 120, note \ 290, 
note l , 327, note \ 

Gruithuisen, 143, 144. 

Gurney, E., 224, note l . 

H. 

Hall, G. S., 186, note V 

Hallucination, and illusion, 11, 
109, 111, 112, 121; and sub- 
jective sensation, 63, 109, 121 ; 
sensory and motor, 66; ner- 
vous conditions of, 112-114; 
incomplete and complete, 113 ; 
as having either central or 
peripheral origin, 113 ; causes 
of, classified, 115 ; in sane 
condition, 116; in insanity, 
118 ; visual and. auditory, 119 ; 
dreams regarded as, 139, 151 ; 
hypnagogic, 143 ; after-dreams 
and ghosts, 183 ; of memory, 
271 ; relation of, to errors of 
belief, 322 ; intuition of ex- 
ternal world regarded as, 355. 



Happiness, feeling of, 200. 

Harmful, illusion as, 188, 229 
292, 339. 

Harmless, illusions as, 124, 292, 
341. 

Hartley, D., 139, 256, note ', 
279. 

Hearing, -as mode of perception, 
34, 48 ; localization of impres- 
sion in, 60 ; sense of direction 
in, 72 ; activity of, in sleep, 
140 ; and muscular sense, 171. 

Heidenhain, Dr., 186-188. 

Helmholtz, H., 22, 23, note ', 44, 
51, 54 and note 1 , 55, note ', 
57, 67, note >, 78, note 1 , 80, 
85, note *, 88, 90, 207, note ». 

Heraclitus, 137. 

Heredity, and illusion of memory, 
280 ; action of, in perpetuating 
intuition, 359. 

Hering, E., 67, note 2 . 

Hodgson, Shadworth H., 347, 
note 2 . 

Holland, Sir H., 277. 

Hood, Thomas, 146. 

Hope, illusory. See Expectation. 

Hoppe, Dr. J. I., 51, 58, note ». 

Horwicz, A., 145, note '. 

Hume, D., 355. 

Huxley, Professor T., 119, note *. 

Hyperassthesia, 65. 

Hypnotism, 185. 

Hypochondria, 65. 

Hypothesis, as illusory, 310, 311. 



Idealism, 348. 

Identity, cases of mistaken, 267. 

Identity, personal, confusion of, in 
dreams, 163 ; consciousness of, 
241, 267, 282, 285; illusory 
forms of, 283 ; gross disturb- 
ances of, in normal life, 287 ; in 
abnormal life, 289 ; momentary 
confusions of, 293. 

Illusion, definition of, 1 ; varieties 
of, 9 ; extent of, 328 ; rationale 
of, 331, 337. 



INDEX. 



367 



Image (physical). See Reflection. 

Image (mental), in perception, 
22 ; seat of, 32 ; in dreams, 
138 ; mnemonic, 236. 

Imagination, play of, in percep- 
tion, 95, 99 ; and sense-illusion, 
106 ; natnre of, in dreaming, 
136, 161 ; as antecedent of 
dream, 152, 158 ; as poetic 
interpretation of natnre, 224 ; 
memory corrupted by effect of 
past, 264, 273, 277 ; present, 
creating the semblance of recol- 
lection, 267, 271; play of, in 
expectation, 305 ; as element 
of illusion generally, 333. 

Immediate. See Cognition. 

Individual, and common experi- 
ence, 26, 27, 137, 209, 214, 336 ; 
dream-experience as, 44, 68 ; 
internal experience as, 209 ; 
memory as, 232 ; belief and 
truth, 338. 

Inference, and immediate know- 
ledge, 6, 334 ; in perception, 
22, 26, 68 ; in belief, 295. 

Innate, recollection as, 280 ; prin- 
ciples, 295, 356. 

Insane, sense-illusions of, 63, 65, 
111 ; hallucinations of, 118 ; 
dreaming and state of, 182 ; 
mnemonic illusions of, 278, 
289 ; beliefs of, 327. 

Insight, nature of, 217 ; illusions 
of, defined, 220 ; passive illu- 
sions of, 220; histrionic illusion, 
222 ; active illusions of, 223 ; 
poetic interpretation of nature, 
224 ; value of faculty of, 228. 

Interpretation, in correct percep- 
tion, 22 ; of impression and 
experience, 70 ; and volition, 
95 ; and fixed habits of mind, 
101 ; and temporary attitude of 
mind, 102 ; of sensations in 
dreams, 137, 147; of internal 
feelings, 203; of others' feel- 
ings, 217 ; of nature by poet, 
225 ; recollection as, 242. 

Introspection, nature of, 14, 189; 



illusory fcrms of, 190 ; con- 
fusion of inner and outer ex. 
perienees, 194 ; inaccurate in. 
spection of feelings, 196; pre- 
sentation and representation 
confused, 199 ; feelings and 
inferences from these, 203 ; 
moral self - scrutiny, 204 ; 
philosophic, 205; value of, 
208. 

Intuition. See Cognition. 

Intuitivism, 348. 



Jackson, Dr. J. Hughlings, 27, 

note 2 , 33, 123, note \ 
Johnson, Dr., 116. 

K. 

Klang, as compound sensation, 

53. 
Knowledge. See Cognition. 



Language, function of, 195. 

Leibnitz, 133. 

Lelut, L. F., 120, note l . 

Lessing, G. E., 133, note l . 

Leuret, 290, note ] . 

Lewes, G. H., 28, 32, note », 52, 
note l , 62, note *, 68, note l , 89, 
note ', 115, note ', 150. 

Life, our estimate of, 323, 326, 
327. 

Light, sensation and perception 
of, 59 ; effects of reflection and 
refraction of, 73 ; represen- 
tation of, in painting:, 88, 91 ; 
action of, in sleep, 140. 

Localization, as local discrimina- 
tion of sensations, 52; as lo- 
calizing of sensations, 59, 60 ; 
illusory, 61, 82; in halluci- 
nation, 118, 119; in dreaming, 
148 ; of events in time, in 
memory, 238, 245 ; in expec- 
tation, 304. 



S68 



INDEX. 



Locke, 133, note '. 

Lotze, H., 60, note *. 

Lover, illusion of, 224, 227, 342. 

Luminosity of painting, 88, 91. 

Lustre, as compound sensation, 54. 

Lyell, Sir Charles, 311. 



Magic, arts of, 73. 

Magnitude, apparent, in vision, 75, 
note 2 ; perception of, in pic- 
torial art, 88, 91 ; of time-in- 
tervals, 245, 249 ; recollection 
of, 268. 

Malebranche, 116. 

Mankind, our views of, 322. 

Matter. See World (material). 

Maudsley, Dr. H., 32, note l . 

Maury, A., 140, 143, 153, note \ 
159, 163, note 1 , 173. 

Mayer, Dr. A., 66, note l . 

Measurement, subjective, of time, 
245. 

Media, coloured, illusions con- 
nected, witli presence of, 82. 

Memory, nature of, 9, 13, 231 ; 
veracity of, 232, 290; defined, 
234; psychology of, 236; 
physiology of, 237 ; localization 
of events in, 238 ; and sense of 
personal identity, 241, 283 ; 
illusions of, 241 ; illusory locali- 
zation, 245, 256 ; distortions of, 
261; hallucinations of, 271; 
illusions respecting personal 
identity, 283 ; relation of, to 
belief, 295 ; compared with 
expectation, 297; and inference, 
335. 

Metempsychosis, 294. 

Meyer, H., 83, 144. 

Mill, J. S., 298, note 2 , 309. 

Mirrors, as means of delusion, 73. 

Misanthropist, 2, 323. 

Mitchell, Dr. Weir, 62. 

Monomania, 111. 

Moral, intuition, 216 ; self-inspec- 
tion, 204. 



Motor illusions. See Muscular 

sense. 
Movement, apparent, 50, 57, 73, 

81, 95, 107; in dreams, 142, 

154. 
Muller, Johannes, 58, note 2 , 100, 

117, 143. 
Muscce volitantes, 118, note 2 . 
Muscular sense, in perception, 23 ; 

illusions connected with, 50, 57, 

62, 66 ; co-operation of, in 

dreams, 142, 154. 
Music, subjective interpretation 

of, 223. 

N. 

Natural selection, effect of, in 
eliminating error, 340. 

Nature, personification of, 224; 
uniformity of, 344, 360. 

Necessity, idea of, 349, 360. 

Nervous system, and condi- 
tions of perception, 31 ; con- 
nections of, 32, 169 ; function 
of, and force of stimulus, 47, 
50 ; prolonged activity of, 55 ; 
specific energy of, 58 ; varia- 
tions in state of, 64; fatigue 
of, 65, 115 ; disease of, ibid. ; 
nervous conditions of halluci- 
nation, 112, 115 ; nervous dis- 
solution and evolution, 122 ; 
condition of, in sleep, 131 ; in 
hypnotic condition, 186 ; ner- 
vous conditions of memory, 237 ; 
nervous conditions of illusion in 
general, 334. 

Normal life, relation of, to ab- 
normal, 1, 121, 124, 182, 277, 
284, note ' ; hallucinations of, 
116. 

O. 

Object, nature of, 36, 353. 

Objective and subjective experi- 
ence, 26, 27, 137, 214. 

Old age, dreams how regarded in, 
276. 



INDEX. 



369 



Oneirocritics, 129. 

Opera, illnsion connected with, 
104. 

Optimism, 323, 327, 342. 

Organic sensations, discrimination 
of, 41 ; interpretation of, 99 ; 
in sleep, 145, 148. 

Organism, conditions of illnsion 
in, 47, 50 ; relation of our con- 
ception of the universe to sen- 
sibilities of, 343. 

Orientation, 125, 138. 



P. 

Pain, recollection of, 264, 270. 

Painting, representation of third 
dimension by, 77; apparent 
movement of eye in portrait, 
81 ; discrepancies between, and 
object in magnitude and lumi- 
nosity, 88 ; realization of, and 
mental preparation, 105 ; reali- 
zation of, by animals, 105. 

Paraesthesia, 68. 

Paralysis of ocular muscles, 66. 

Passive, and active factor in per- 
ception, 27 ; and active illusion, 
45. 

Percept, 22 ; and sense-impres- 
sion, 59. 

Perception, a form of immediate 
knowledge, 10, 13, 17, 18; 
external and internal, 14 ; 
philosophy of, 14, 20, 22, 36, 
346, 348, 353, 355, 359; illu- 
sions of, 19, 35 ; psychology of, 
20; and inference, 22, 26, 76; 
physiological conditions of, 31. 

Persistent objects, representation 
of, 312. 

Persistent self. See Personal 
identity. 

Personal equation, in perception, 
101 ; in aesthetic intuition, 214 ; 
in memory, 292 ; in ,belief, 324. 

Personal identity, consciousness 
of, 241, 282, 285; illusions con- 
nected with, 283 ; disturbances 

17 



in sense of, 287; sense of, in 
insanity, 289 ; momentary con. 
fusions of, 293 ; philosophic pro. 
blem of, 285, 354, 360. 

Personification of nature, 224. 

Perspective, linear, 79, 97, 98; 
aerial, 80; of memory, 245. 

Pessimism, 323, 327. 

Phenomenalism, 348. 

Philosophy, conception of illusion 
by, 7, 36, 205, 285, 349 ; of mind, 
132, 285, 344, 348; as theory 
of knowledge, 295, 346 ; and 
science, 346, 348 ; and common 
sense, 347, 349; problems of, 
347. 

Phosphenes, 58. 

Physical science. See Science. 

Plato, 281. 

Platonists, 349. 

Pleasure, feeling of, 200; recol- 
lection of, 264, 270. 

Plutarch, 133, note *. 

Poetry, lyrical and dreams, 164; 
misinterpretation of, 223 ; per- 
sonification, 224. 

Points, discrimination of, 52. 

Poisons, action of, 115. 

Pollock, P., 184, note \ 

Pollock, W. H., 184. 

Predisposition, action of, in per- 
ception, 44, 101, 102; in aes- 
thetic intuition, 215; in in- 
sight, 223 ; in recollection, 268; 
in belief, 305, 319; belief as, 
324. 

Prejudice. See Predisposition. 

Prenatal experience, recollection 
of, 281. 

Preperception, 27; illusions con- 
nected with, 44, 93 ; voluntary, 
95 ; result of habit of mind, 
101 ; result of temporary con- 
ditions, 102; as sub-expectation, 
102; as definite expectation, 
^106. 

Presentation and representation, 
9, 10, 13, 14, 192, 234, 329, 330. 

Projection, outward, of sensa- 
tions, 63 ; of mental image, 111, 



>70 



INDEX. 



112 ; of solid form on flat, 79, 
81, 96. 

Prophetic, dreams as, 129, 147, 
note l ; enthusiast, 307. 

Psychology, popular and scientific, 
9, 10 ; distinguished from philo- 
sophy, 14, 36, 345, 352 ; intro- 
spective method of, 208; as a 
kind of philosophy, 305. 

Public events, localization of, by 
memory, 258. 

E. 

Eadestock, P., 130, note 1 , 132, 
note », 134, note l , 140, 141, 
149, note », 162, 182, 275. 

Rationalism, philosophic, 348. 

Realism, 348. 

Reality, nature of, 36, 346. 

Recognition, and perception, 24, 
25 ; illusions of, 87 ; and 
memory, 234. 

Reflection (of light), illusions con- 
nected with, 73, 83. 

Refraction and optical illusion, 73. 

Relative, sensation as, 64; atten- 
tion to magnitude and bright- 
ness as, 91; estimate of duration 
as, 249. 

Relief, illusory perception of, 75, 
96. 

Representation and presentation, 
9, 10, 13, 14, 192. 

Retrospection. See Memory. 

Ribot, T., 238, note \ 290, note K 

Richter, J. P., 143. 

Robertson, Professor G. C, 35, 
note *. 

Romanes, G. J., 105, note 2 , 250, 
note 2 . 

Rousseau, 280. 

S. 

Savage, dream theory of, 128 ; 

idea of nature of, 225. 
Schemer, C. A., 140, 149. 
Schopenhauer, A., 145, 342. 
Schroeder, H., 85. 



Science, philosophy and, 8, 36 ; 
285, 344; conception of the 
material world in physical, 36, 
343, 346, 347 ; and common cog- 
nition, 338, 357. 

Scott, Sir W., 116, 125. 

Secondary qualities, 36, 344. 

Selection, process of, in per- 
ception, 95 ; in dreams, 174 ; in 
memory, 257, 263. 

Self, confusion of, in dreams, 163 ; 
introspective knowledge of, 192; 
self-deception, 200 ; identity of, 
241, 282, 285 ; confusion of pre- 
sent and past, 267, 284 ; dis- 
turbances in recognition of, 287, 
289 ; momentary confusions of, 
295 ; confusion of present and 
future, 305. 

Self-esteem, illusion of, 315 ; 
origin of, 319 ; utility of, 342. 

Self-preservation, 320. 

Sensation, element in perception, 
20; discrimination and classifi- 
cation of, 21 ; interpretation of, 
22; inattention to, 39, 87; 
modified by central reaction, 39, 
87, 89, 91 ; confusion of novel, 
40 ; indistinct, 41 ; misinter- 
pretation of, 44 ; relation of, to 
stimulus, 46, 50 ; limits to dis- 
crimination of, 52; after-im- 
pression, 55 ; subjective, 59, 62, 
107, 143 ; localization of, 59. 

Sensibility, limits of, 50; varia- 
tions of, 64. 

Sensualism, philosophic, 348. 

Shadow, cast-, 77. 

Shakespeare, 3. 

Sight, mode of perception, 19, 33, 
34, 48, 49 ; local discrimination 
in, 52 ; single vision, 54 ; 
localization of impression in, 60; 
in sleep, 139; images of, in sleep, 
150, 154. 

Single, vision, 54; touch, 72. 

Sleep, mystery of, 127; physiologv 
of, 131. 

Sleight of hand. See Conjuror. 

Smell, as mode of perception, 34, 



INDEX. 



371 



note '; localization of impres- 
sion in, 60 ; subjective sensa- 
tions of, 108 ; in sleep, 141 ; 
and taste, 171. 

Solidity, illusory perception of, 
75, 96. 

Spaoe, representation of, 207. 

Specific energy of nerves, 58. 

Spectra, ocular, etc. See Subjec- 
tive sensation. 

Spencer, Herbert, 32, note ', 128, 
note ', 323, 340. 

Spinoza, 143, 1S4. 

Spiritualist seances, 103, 107, 123, 
265. 

Stereoscope, 75. 

Stewart, Dugald, 172, 306. 

Stimulus, qualitative relation of, 
to sensations, 46, 58, 67 ; quan- 
titative relation of, to sensation, 
50, 64 ; after-effect of, 55 ; pro- 
longed action of, 56 ; subjective 
or internal, 62 ; exceptional 
relation of, to organ, 70 ; action 
of, in sleep, 135, 139, 143; in 
hypnotic condition, 188. 

Strunipell, L., 144, 147, note 2 . 

Subjective, experience, 26, 27, 
137, 214; movement, 51, 57; 
sensation, 59, 62, 107, 113, 121, 
143. 

Suggestion, by external circum- 
stances, 30, 44, 89, 91, 267; 
verbal, 30, 106, 183, 215, 238, 
301, 310. 

Symbol, dream as, 129, 149. 

Sympathy, basis of knowledge, 
223 ; and illusion of insight, 
223; and illusion of memory, 
277 ; and momentary illusion, 
293. 

T. 

Taine, H., 60, note \ 108, note 3 , 
117, note \ 137, 293, note l , 
356, note '. 

Taste, aesthetic. See .iEslhelic in- 
tuition. 

Taste, localization of impress'on 



in, 60 ; subjective sensations of, 
63 ; variations in sensibility, 
68; activity of, in sleep, 141 
and smell, 171. 

Temperament, a factor in sense- 
illusion, 101 ; in dreams, 137 ; 
in illusory belief, 325; in illu- 
sion generally, 334, note l . 

Temperature, sense of, 65. 

Tennyson, A., 226. 

Testa, A. J., 131. 

Testimony, of consciousness, 205 ; 
fallacies of, 265 ; to identity, 
267. 

Thaumatrope, 56. 

Theatre, illusion of the, 104, 222 ; 
self-deception of the actor, 200. 

Thompson, Professor S. P., 51, 
note l . 

Thought, in relation to belief, 326. 

Time, retrospective idea of, 239, 
246, 250 ; constant error in 
estimate of, 245 ; subjective 
estimate of, 249 ; contempora- 
neous estimate of, 250 ; sense 
of, in insanity, 290 j prospective 
estimate of, 303. 

Touch, as form of perception, 33, 
34, 49 ; local discrimination in, 
52; subjective sensations of, 62; 
variations in sensibility of, 65 ; 
in sleep, 141. 

Transformation, in perception, 94; 
of images in dreams, 163 ; ia 
memory, 262, 267 ; in expecta- 
tion, 305. 

Trick. See Conjuror. 

Tuke, Dr., 110. 

Tylor, E. B., 128, note l . 

U. 

Unconscious, inference, 22, 68, 
269, 335, note 1; mental activity, 
133, 235; impressions, 41, 152. 

Useful. See Beneficial. 

V. 

Tanity. See Self-esteem. 
Venn, J., 299, note >. 



372 



INDEX. 



Ventriloquism, 82. 

Verification, of sense-impression, 

38, 351 ; of self -inspection, 210 j 

of memory, 291. 
Verisimilitude, in art, 80, 88 ; in 

theatrical representation, 104 ; 

in dreams, 168. 
Vierordt, 245. 
Vision. See Sight. 
Visions, 1, 110 ; dreams regarded 

as, 128, 131. 
Vital sense. See Coensesthesis. 
Voice, internal, 119, 194 ; activity 

of, in dreams, 155. 
Volition, and perception, 95 ; ab- 
sence of, during sleep, 137, 172 ; 

co-operation of, in correction of 

illusion, 352. 
Volkelt, J., 172. 



W. 

Weber, E. H., 43. 

Weinhold, Professor, 186. 

Wetness, perception of, 53. 

Wheatstone, Sir C, 75. 

Wheel of life, 56. 

Will. See Volition. 

Wordsworth, W., 281. 

World, our estimate of, 323, 326, 
327; scientific conception of 
material, 8, 36, 343, 344 ; reality 
of external, 344-346, 349, 353, 
355, 360. 

Wundt, Professor, W. 13, note ', 
31, note l , 32, note l , 58, note *, 
67, note 2 , 75, 93, note V 118, 
note 3 , 136, note l , 139, 143, 
177, 246, 247, note », 251, 252, 
254. 



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48. ORIGIN OF CULTIVATED PLANTS. By Alphonse de Candolle. $2.00. 

49. JELLY-FISH, STAR-FISH, AND SEA-URCHINS. Being a Research on 

Primitive Nervous Systems. By Geoege J. Romanes. $1.75. 

50. THE COMMON SENSE OF THE EXACT SCIENCES. By the late Will- 

iam Kingdon Clifford. $1.50. 

51. PHYSICAL EXPRESSION: Its Modes and Principles. By Francis Wae- 

ner, M.D., Assistant Physician, and Lecturer on Botany to the London 
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52. ANTHROPOID APES. By Robeet Haetmann. Professor in the University 

of Berlin. With 63 Hlustrations. $1.75. 



New York : D. APPLETON & CO., 1, 3, & 5 Bond Street. 



The International Scientific Series— (Continued.) 



53. THE MAMMALIA IN THEIR RELATION TO PRIMEVAL TIMES. By 

Oscar Schmidt. $1.50. 

54. COMPARATIVE LITERATURE. By Hotcheson Macaulay Posnett, 

M. A., LL. D., F. L. S., Barrster-at-Law ; Professor of Classics and English 
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55. EARTHQUAKES AND OTHER EARTH MOVEMENTS. By John Milne, 

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56. MICROBES, FERMENTS, AND MOULDS. By E. L. Teouessaet. With 

107 Illustrations. $1.50. 

57. THE GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION OF ANI- 

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58. WEATHER. A Popular Exposition of the Nature of Weather ChangeB from 

Day to Day. By Hon. Ralph Abercromby. $1.75. 

59. ANIMAL MAGNETISM. By Alfred Binet and Charles Fere, Assistant 

Physician at the Salpetriere. 




3350 



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